R. PHY-1(ICSE)

1) What force and what weight will be acting on a mass of 10.5 kg being poled by the Earth ? g= 10ms⁻².     (2)

2) What is a pure spectrum of light ?    (2)

3) Distinguish between a real and a virtual image.     (2)

4) Show , using a ray diagram, how a converging lens can be used to form a virtual image.    (2)

5) What is the difference between forced and natural vibrations ?    (2)

6) With the help of simple diagram, show that mechanical advantage of a single fixed pulley is 1 and that of a single movable pulley is 2.      (2)

7) Give one advantages and one disadvantage of connecting electric cells in parallel.  (2)

   

8) How much does it cost to run one heater of 1000 W and two electric bulbs of 40 W each for eight hours if one unit of electricity cost Rs2.     (2)

9) Why is it dangerous to use wet hands to put off a switch ? What purpose does a fuse serve in a circuit ?    (1+1)

10) What is the source of sun's energy ? Which element give rise of this energy?   (1+1)

11) Give two properties of X-rays.    (2)

12) State two factors that effect the fundamental frequency of vibration of a stretched string.    (2)

13) A Truck driver can load oil drums into the back of the truck by pushing them up a sloping plank or lifting them directly. Each drum has a mass of 80 kg., the plant is 3m long and back of the truck 0.8m above the ground.

a) How much force will be needed to lift a drum into the truck directly, without using the plank. (Take g= 10 m/s²)?     (1)

b) How much energy would be converted in lifting drum into the truck without the plank ?     (2)

c) if the force needed to push a drum up the plank is 300N, why is this less than the answer to part (a)?     (2)

d) When the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck .     (3)

e) The driver has to stop at the factory gates . What happens to the kinetic energy of the truck ?     (2)

14) Difference between the following:

a) noise and a musical note.

b) frequency and wavelength of sound. (4)

15) The human ear can detect continuous sounds in the frequency range 20 Hz to 20000 Hz. Assuming speed of the sound in air is 330 m/s for all frequencies , calculate the wavelength corresponding to given extreme frequencies of the range.    (2)

16) Give reason for the following:

a) The same musical note when played on a piano and played on a flute sounds different.      (2)

b) Soldier often March 'out of step' while crossing bridges.     (2)

17) The diagram shows a part of electrical system which operates some of the lights.

a) The diagram only Shows one lead from the battery to each bulb, but a complete circuit most have two. How does the current get back to the battery ?  (2)

b) if a car owner adds extra lights to the car, why must the paint be removed from the body-work where the electrical contact is made ?  (2)

c) The two rear lights wired up incorrectly, and only light faintly.

    i) why do they only light faintly?

   ii) Draw a diagram to show how the wires should be connected to make the lights work normally.      (2)

d) There are four side lights, and a number plate light (i.e., a total of five lights). Each bulbs is labelled 12V, 4W

   i) what does the label mean ?

 ii) How much current flows through each bulb (assuming it is connected properly)?

 iii) How much current does the battery supply to these bulbs altogether (i.e., in total)?     (3)

e) If the lights are on, they go dim when the car is started. Why is this?      (2)

18) a) Which would be the worse , the burn you get holding your hand in a jet of steam or that got from boiling water, both at 100°C ? Give a reason for your answer.    (2)

b) In an experiment to measure the specific heat capacity of brass, 0.2 kg of hot water, at a temperature 65°C, was poured into a heavy brass container of mass 1.5 kg, initially at 15°C. After stirring, the final temperature reached was 45°C. Assume that the specific heat capacity of water is 4200 J/kg/°C.

   i) Calculate the heat energy released by the hot water in cooling from 65° C to 45°C.

ii) Assume that the heat energy calculated in part (i) is given by the brass container in raising its temperature from 15°C to the final common temperature of 45°C. Calculate the heat energy observed by the brass container per °C rise in temperature.

iii) Using the result obtained in part (ii), calculate the specific heat capacity of brass.    (5)

19) After robbery, if a window has been broken there will be tiny particles of glass. Some of these will be found at the scene of the crime and some maybe caught in the thief's clothing. If the police can prove that these particles are identical, they have a strong case.

A method of doing this is to suspend the particles of glass in a special liquid. Light of a single colour is shone through the liquid and the particles viewed through a microscope. The temperature of the liquid is then slowly altered . This alters the speed of light through the liquid (i.e., it alters the refractive index).  At one particular temperature the particles of glass disappear. If this happens at the same temperature for both sets of glass particles , they probably came from the same broken pane of glass.

a)  Complete a copy of the diagram to show how light bands when it travels from the liquid to the glass and black to the liquid,

   i) if the lights slows down in the glass.

  ii) if the light speeds up the in the glass.     (4)

  

b)  why is the light used in the police work a single colour ?     (2)

  

c) Under what two circumstances can light moving from a liquid to glass pass straight on without bending ?     (2)

d) When do the particles of glass disappear in the police method ?

20) The emmission of an α-particle or emission of β-particle is nearly always accompanied by what is known as γ-radiation.

   i) How does the ionising power of γ-radiation compare with that of α- and β-particles ?

  ii) Is γ-radiation more or less penetrating then α- and β- particles?

 iii) Is it possible to deflect γ- radiation in the ways that α and β-particles can be deflected, using electric or magnetic fields ?

  iv) What is γ-radiation thought to be ?       (4)

b) Radium- 226 (²²⁶Ra₈₈) is radioactive and emits α-particles.

 i) By how much does the atomic number of a radium nucleus (²²⁶Ra₈₈) change when an α-particle is emitted ?

 ii) By how much does the mass number of the radium nucleus in part (i) change?

 iii) The new nucleus formed, when a nucleus of (²²⁶Ra₈₈) emits an α-particle is identified as a nucleus of another element fairy close to radium in the periodic table. Identify this element from the data: Polonium (Po₈₄), Astatine (At₈₅), Radon (Rn₈₆) and Francium (Fr₈₇).      (3)

c) State three major uses of X-rays.      (3)

FORCE

A) Complete the following sentences by choosing appropriate words from the box:

( kg ms⁻¹, centripetal, same, 1000, velocity, newton, mass, force, momentum, masses, 10⁵, spring, 9.8 x 10⁵, centre)

1) Force produces an acceleration in the_____ direction as the force.

2) Inertia is directly proportional to the_____ of the body.

3) Force of 1 newton produces an acceleration of ____ ms⁻² in a mass of 1 g.

4) The SI unit of weight is_____.

5) The SI unit of momentum is _____.

6) Force  = Rate of change of _____.

7) Weight of a body is measured by a _____ balance.

8) When a shot is fired from a gun, the velocity of the gun and bullet are inversely proportional to their ______.

9) The weight of a body is zero at the _____ of the earth.

10) The acceleration towards the centre in circular motion is called the__ acceleration.

11) One newton= _____ dyne.

12) Momentum = mass x ______.

13)  1 kgf _____ dyne.

14) The acceleration produced in a body is directly proportional to the____ applied on it.

B) State whether true or false

1) When an object undergoes an acceleration, a force always acts on it.     

2)  The mass of a body cannot be zero.    

3) To every action there is an equal and opposite reaction.     

4) The mass of a body is constant for a body at ordinary speed.    

5) A body can have weight but no mass.  

6) The weight of a body changes from place to place.    

7)  The momentum of a body depends on its mass and the velocity.   

8) The force of gravity acts vertically upwards at the centre of gravity of a body.   

9) The moment of a body is the product of the mass of the body and acceleration.m. 

10) The weight of an object on the moon is about one-fifth of its weight on the earth.   

11) It is difficult to stop a tennis ball than a cricket ball moving with the same speed.        

C) Very Short Questions:

1) What law of motion gives us the mathematical measurement of force ?

2) Is a force needed to keep a body moving with uniform velocity?

3) Write SI unit of

a)  mass.     

b) force.      

4) What is the relation between SI and CGS units of force?

5) State the SI and CGS units of mass. How are these units related ?

6)  Write an expression for the momentum of a body.

7) Give its SI and CGS units of force.

8) Define the term 'linear momentum ' Give its SI unit.

9) Is momentum a scalar or a vector quantity ?

10) On what factor does the inertia of a body depend ?

11) What is the relation between kilogramme force and newton ?

12) State the relation between force, mass and acceleration.

13) State the SI and CGS units of weight.

14) Name the physical quanty whose unity is kg ms⁻¹.  

15) Name the physical quantity whose unit is newton. 

16) How is the weight of a body related to its mass?

17) State the relation between the momentum of a body and the force acting on it.

18) On what factor does the momentum of a body depend ?

19) What is the total moment of the bullet and the gun before firing ?

20) What name is given to the product of mass and velocity of a body ?

21) Which physical quantity corresponds to the rate of change of momentum?

22) A force is applied on 

i) a non rigid object and 

ii) a rigid object.

How does the effect of the force differ in both cases?

23) State the SI unit of momentum of a body.

D) Short Answer Type Questions:

1) Will a body weight more in air or in vacuum when weighed with a spring balance ? Give a reason for your answer.

2) Bodies of larger mass need greater initial effort to put them in motion. Why ?

3) Give the magnitude and direction of the net force acting on:

a) a drop of rain falling down with a constant speed.

b) a cork of mass 10g floating on water.

c) A kite skillfully held stationery in the sky.

d) A car moving with a constant velocity of 30 km h⁻¹ on a rough road.

4) Derive a relation between SI and CGS unit of force.

E) Multiple Choice Questions 

1) When a freely moving object of mass 1 kg is subjected to a force of 1N, it moves with:

a) a speed of 1 ms⁻¹ 

b) a peed of 1 kms⁻¹

c) an acceleration of 1 ms⁻²

d) an acceleration of 10 ms⁻²

2) When a net force acts on an object, it will be accelerated in the direction of the force with an acceleration proportional to 

a) the force on the object.

b) the velocity of the object.

c) the mass of the object.

d)  the Inertia of the object.

3) a force:

a) cannot start or stop the motion of a body.

b) can change the speed or direction of motion or both of a moving body.

c) cannot bring a change in dimensions of a body 

d) none

4) When an object undergoes an acceleration:

a) its velocity always increases.

b) its speed always increases.

c) it always falls towards the Earth.

d) a force always acts on it.

5) The force required to produce an acceleration of 5 ms⁻¹ in an object of mass 2 kg is:

a) 2.5N b)?10.0N c) 0.4 N d) 7.0 N

6) 1N is the force which produces.

a) an acceleration of 1ms⁻² in a body of mass 1 g.

b) an acceleration of 1cms⁻² in a body of mass 1kg.

c) an acceleration of 1cms⁻² in a body of mass 1kg.

d) an acceleration of ms⁻² in a body of mass 1kg.

7) The correct relationship between the force, mass and acceleration is:

a) F= a/m b) F= ma² c) F= ma d) F= m/a

8) External force acting on an object:

a) are always balanced 

b) are always unbalanced 

c) may or may not be balanced. d) none

9)  a body X has a mass of 30 kg and is moving with the velocity of 10 ms⁻¹. Another body Y has a double mass but half of the velocity. The momentum are in the ratio of 

a) 1:2 b) 1 : 1 c) 1:4 d) 2:1

10) The rate of change of momentum gives :

a) moment b) impulse  c) force d) acceleration

11)  Mass is given by the relation

a) velocity/acceleration 

b) force/velocity

c) force.acceleration 

d) distance/velocity 

12) The momentum of a heavy at rest will be :

a) large b) small c) zero d) none

13) The SI unit of momentum is:

a) dyne  b) newton c)!kg ms⁻¹ d) cms⁻²

14) The momentum of a toy car of mass 400 g moving with a speed of 5 ms⁻¹ is:

a) 1 mg ms⁻¹ b) 2kgms⁻¹ c) 10kg ms⁻¹ d) 5 kg ms⁻¹

15) If the mass of a body is m kg, its weight will be:

a) m g  b) mg N c) m dyne d) none

16) If the mass of a body and the force acting on it are both doubled :

a) its acceleration will become double

b) there will be no change in its acceleration.

c) its acceleration will become half 

d) none 

17) 1 kg weight is equals to:

a)  9.8N b) 98 c) 980 N d) 9.8 dyne 

18) The weight of an object:

a) refers to its inertia

b) is the force with which it is attracted by the earth.

c) is the gravity of matter it contains.

d) none

19) An object undergoes an acceleration of 8ms⁻¹ starting from rest. The distance travelled in 1 second is:

a) 2m b) 4m c) 6m d) 8m

ANALYTICAL CHEMISTRY

Very Short Questions 

A)1) "When an aqueous solutions of Ammonium hydroxide is added to zinc sulphate solution, a red percipitate of zinc hydroxide is obtained, which is insoluble in excess of Ammonium hydroxide solution." Is this statement correct ? If not, correct it.

2) "When solutions of ammonium hydroxide and copper sulphate are mixed , no precipitate is formed ." This statement is incorrect. Correct the statement.

3) State the colour of the participate observed when caustic soda solution is added to the zinc sulphate solution (prepared in water).

4) Write the balanced chemical equation to show the reaction of magnesium chloride solution and ammonium hydroxide.

5) State the colour of the precipitate formed when ammonium hydroxide is added drop by drop and then in excess to aqueous solution of the magnesium chloride.

6) How does sodium hydroxide solution act in distinguishing iron(II ) chloride from iron(III ) chloride solution ?

7) Write balanced equation for the following reaction.

Aluminium powder is warmed with hot and concentrated caustic soda solution.

8) Write balanced chemical equation for the following reaction:

 Aluminium oxide and sodium hydroxide solution.

B) Give reasons :

1) A solution of ferrous chloride in water, which is very light green, changes into reddish brown colour when exposed to air for some time.

2) Green coloured crystals of ferrous sulphate turns brown when exposed to air for a long duration of time.

C) Fill in the blanks by choosing the correct word/s given within the brackets 

1) The formula of sodium plumbate is____.(NaPbO₂/Na₂PbO₂)

2) The colour of hydrated zinc sulphate is_____.(blue/white)

3) On adding aqueous solution of Ammonium hydroxide to ferric chloride, a ____ colour precipitate of ferric chloride is formed . (reddish brown/ sky blue)

4) The valency of copper in copper sulphate is_____. (One/two )

5) Zinc chloride solution reacts with caustic soda solution to give a ____ coloured precipitate . (Red/white)

6) The salt of lead, soluble in hot water and insoluble in cold water is ____. (lead sulphate/ lead chloride)

D)  Name the following:

1) The precipitate formed when NaOH solution is added to FeSO₄ solution.      

2) The products formed when NH₄OH solution is added to CuSO₄ solution in excess .    

3) The colour of the precipitate formed on adding sodium hydroxide solution to MgCl₂ solution.    

4) The colour of the precipitate formed on adding NH₄OH solution to MgCl₂ solution.   

5) The products formed when ZnSO₄ solution is added to sodium hydroxide solution in excess.    

6) A solution of this compound gives a dirty green precipitate with Sodium hydroxide.  

E) State whether True or False:

1) A reddish brown precipitate is formed when iron (III) chloride and sodium hydroxide solutions are mixed.     

2) When copper sulphate solution is treated with sodium hydroxide solution,  a pale blue percipitate of copper(II ) hydroxide is formed.     

3) The colour of percipitate of Mg(OH)₂ is dull white.     

4) On adding aqueous solution of Ammonium hydroxide to lead nitrate solution, a green percipitate is formed, which is insoluble in excess of Ammonium hydroxide.    

Short Questions 

1) How would you convert:

a) aluminium into potassium metaluminate ?

b) zinc into potassium zincate

2) Give equations for the action of aluminium with sodium hydroxide and potassium hydroxide.

3) Give equations for the action of aluminium oxide with concentrated sodium hydroxide and potassium hydroxide.

4) How will you distinguish between MgSO₄ and ZnSO₄ by studying their reaction with NH₄OH ?

5) a) What are amphoteric oxides ?

b) Why these oxides react with NaOH ?

6) Write down equation for each of the following reactions:

a) Solution of the ammonium chloride in sodium hydroxide are mixed and heated.

                           

b) copper sulphate solution is added to sodium hydroxide solution 

7) Three test tubes contain calcium nitrate solution, zinc nitrate solution and lead nitrate solution respectively . Each solution is divided into two portions. Describe the effect of:

a) adding sodium hydroxide solution to each portion in turn till it is in excess.

b) adding Ammonium hydroxide to each portion in turn till it is in excess.

8) Sodium hydroxide solution can be used to distinguish between iron(II) sulphate solution and iron(III) sulphate solution because these solutions give different coloured precipitates with sodium hydroxide solution. Give the colour of the precipitate formed with:

a) iron(II) sulphate solution.   

b) iron(III) sulphate solution.       

9) State what do you observe when :

a) neutral litmus solution is added to an alkaline solution.

b) ammonium hydroxide is added to iron(III) sulphate solution.

10) How do you distinguish between Zn²⁺ and Pb²⁺ using Ammonium hydroxide solution ?

Each Question Carries 3 Marks:

1) State the colour of the following salts:

a) copper chloride.     

b) copper nitrate .    

c)!ferric chloride.    

d) lead nitrate. 

e) magnesium carbonate.  

f) zinc hydroxide.    

2) State the colour of the aqueous solution of the following salts :

a) magnesium sulphide crystals.       

b) ferrous chloride crystals.      

c) ferric chloride crystals .    

d) ferrous sulphate crystals .   

e) ferric sulphate crystals .       

f) copper sulphate crystals.   

3) Give the chemical equation to show the reaction between caustic soda solution and:

a) zinc oxide.

b) Aluminium oxide. 

c) lead oxide.

4)  State the colour of the percipitates formed when ammonium hydroxide is added drop by drop and then in excess to aqueous solution of:

a) calcium chloride.    

b) zinc sulphate.    

c) lead nitrate.   

d) ferrous sulphate.   

e) ferric chloride.   

f) copper sulphate.  

5)  How does Sodium hydroxide react with the following salts ?

a) ZnSO₄.

b) CuSO₄

c) FeSO₄

6) Describe the action of NH₄OH on the following:

a) CuSO₄

b) Fe₂(SO₄)₃

c) FeSO₄

7) Complete the following equations:

a) Zn(OH)₂ + NaOH---> _______+ ____

b) _____ + NaOH ---> Fe(OH)₃ + NaCl.

c) Zn(OH)₂ + NH₄OH ---> _____+ ____

      

Long Type Questions:

1) Give balanced chemical equations to show the reaction of:

a) lead and caustic soda solution.

b) aluminium and caustic Potash solution. 

c) lead oxide with caustic soda solution.

d) ferrous chloride with Ammonium hydroxide. 

2) State the colour of the percipitate observed when caustic soda solution is added to each of the following solutions (prepared in water):

a) copper sulphate crystals.    

b) ferrous sulphate crystals.  

c) ferric chloride crystals. 

d) magnesium sulphate crystals.

e) lead nitrate crystals.    

f) zinc chloride crystals.

g) magnesium chloride.    

h) calcium chloride. 

3)  Give the reactions of Ammonium hydroxide with the formation :

a) zinc chloride solution.

b) ferric chloride solution.

 

c)  copper chloride solution.

d) magnesium sulphate solution.

e) ferrous sulphate solution.

f) lead nitrate solution.

g) zinc sulphate solution.

4)  Write balanced equations for the action of zinc and lead with:

a) Sodium hydroxide.

b) potassium hydroxide.

5) Give equation for the action of zinc oxide and lead oxide with concentrated sodium hydroxide and potassium hydroxide.

6)  What is the action of KOH on:

a) CuSO₄

b) MgSO₄.

c) ZnSO₄

 d) Fe₂(SO₄)₃

7) Complete and balance the following equations:

a) CuSI₄+ ____   ---> Cu(OH)₂+ (NH₄)₂SO₄

b) Al + NaOH + ____ ---> ____+ H₂

c) PbO + NaOH-->]____+ ____

d) ____+ NaOH---> NaAlO₂+ ______ .

8) What products are found when :

a) aqueous solution of NH₄OH is treated with zinc sulphate solution ?

b) Sodium hydroxide is added to is added to MgSO₄(aq) ?

c) NaOH(aq) is added to Pb(NO₃)₂ solution ?

d) NaOH(aq) is treated with Al₂O₃?

9) Using sodium hydroxide solution. how would you distinguish

a) Ammonium sulphate from sodium sulphate ? 

b) zinc nitrate solution from calcium nitrate solution ?

c) Iron (III) chloride (ferrous chloride) solution from iron(III) chloride (ferric chloride)  solution ?

d)  lead hydroxide from magnesium hydroxide ?

1) Complete and balance the following equations:

a) KOH + H₂SO₄ --> ____+ ___

b) ____+ HNO₃---> Pb(NO₃)₂ + ____.

c) CaCl₂ + ____ --> Ca(OH)₂+ NaCl

d) ____+ ____ --> Pb(OH)₂+ NaNO₃ 

e) Pb(OH)₂ + NaOH ---> ___+ ____

2) a) Sodium hydroxide solution is added to solution A. A white precipitate is formed which is insoluble in excess sodium hydroxide solution. What is the metal ion present in solution A ?

b) When ammonium hydroxide is added to solution B, it gives an a inky blue solution. What is the cation present in solution B ? What is the probable colour of solution B ?

c) When an ammonium salt is warmed with sodium hydroxide solution, ammonium gas is evolved. State three ways in which you could identify this gas.

POLLINATION & FERTILIZATION

A) Definition:

1) Abiotic agents

 

2) Anemophily

3) Antipodal cells

4) Artificial pollination

5) Biotic agents

6) Cheiropteriphily

7) Cleistogamy

8) Dichogamy

9) Egg (or female gamete)

10) Embryo

11) Embryo sac

12) Endosperm 

13) Entomophily

14) Exine

15) Fertilization

16) Funicle

17) Germ pore 

18) Heterostyly 

19) Herkogamy

20) Homogamy

21) Hydrophily

22) Integument 

23) Intune

24) Malacophily

25) Micropyle

26) Nectar

27) Nectar

28) Nectar guide

29) Ovule

30) Polar nuclei

31) Pollination

32) Protoandry

33) Protogyny

34) Seed

35) Synergids

36) Zygote (or oospore)

37) Double fertilization

B) 1) Define pollination. How does it differ from fertilization?

2) Give two advantages and disadvantages of self pollination.

3) Give two advantages and disadvantages of cross pollination.

4) State 4 difference between insect and wind pollinated flowers.

5) Give two examples each of wind and insect pollinated flowers.

6) Normally sepals fall after fertilization. Name two fruits in which the sepals persist.

7) Mention whether the following statements are True or False:

a) Fertilization is fusion of anther and stigma.    

 

b) Cross pollination always occurs in unisexual flower.    

c) The generative nucleus in the pollen grains develops into two male gametes.    

d)  In maize the pollination is brought about by insects.    

e) Anemophilous flowers are large and bright.     

f) Vallisaneria flowers are pollinating by wind.     

8) Name the floral parts which develop into following structures :

a) seed.

b) pericarp.     

c) seed coat.

d) fruit.         

9) What is the function of pollen tube? Trace its path from stigma to the female gametes by means of diagram.

10) Explain the following terms:

a) Anemophilous flower 

b) Double fertilization 

c) Glametes 

 

d) Oospore 

e) Nectar guides 

11) Difference between the following:

a) Pretendory and Protogyny 

b) Self pollination & cross pollination.

c) Fruit & Seed.

    

d) Tube nucleus and the Generative nucleus

e) Ovule & Seed.

12) Draw a  labelled diagram of ovule as seen in a section.

13) The diagram alongside shows a section through a flower at two stages of development.

Observe the diagram and answer the following questions:

a) Write down two features in the diagram to show that the flower is insect pollinated.

b) What information shown in the diagrams would suggest that cross pollination takes place in the flower?

14) Fill in the blanks with appropriate word given in the brackets.

a) Cross pollination takes place in all ____plants.(monoecious /dioecious)

b) Bougainville flowers are pollinated by____. (wind/insects /water)

c) double fertilization is common in ___. (Gynosperms/ angiosperms)

d) Salvia is a _____ flower. (Entomophilous/ornithophilous/hydrophilous)

e) After fertilization, the _____ becomes the fruit and the ___ becomes the seed. (Ovule/ovary/integument)

REFRACTION THROUGH PLANE

Very Short Questions 

1) What do you understand by the term 'refraction of light'?

2) What is the cause of refraction of light

3) Define the term 'angle of incidence'

4) what do you understand by the term 'angle of refraction'?

5) Define angle of deviation.

6) What do you understand by the term 'refractive index of a medium'?

7) What is the refractive index of an opaque body ?

8) Which material among the reflective index media has maximum refractive index?

9) What is the refractive index of :

a) vacuum b) water

10) What is the unit of refractive index ?.

11) On what factors does the refractive index of medium depend ?

12) What is the principle of reversibility of light ?

13) How the angle incidence (i), angle of emergence (e), angle of prism (A) and angle of deviation (δ) are related to each other ?

14) What is the relation between the angle of incidence i in the air and the angle of refraction r in the glass ?

15) What do you understand by the term 'lateral displacement'?

16) Does total internal reflection occurs when light passes from a rather medium to a denser medium?

17) Define prism.

18) A light ray is incident from a denser medium on the boundary separating it from a rarer medium at an angle of incidence equal to the critical angle. What is the angle of refraction for the ray?

19) State the approximate value of the critical angle for glass-air surface.

20) Define the critical angle.

21) Write down a relation between the refractive index and the critical angle.

22) States Snell's law of refraction.

23) What is the angular deviation of the emergence ray from the glass block with respect to the incident ray ?

24) a) What is an optical fibre ?

b) give one practical use of optical fibre.

Short Questions:

1) State the law of refraction.

2) Define absolute refractive index of a medium.

3) The refractive index of water with respect to air is ₐμₕ and that of glass with respect to air ₐμₕ. Express the refractive index of glass with respect to water.

4) How is the refractive index of a medium is related to the speed of light in it ? For which colour of white light, the refractive index of a transparent medium is the least ?

5) Distinguish between the ordinary reflection and total internal reflection. 

a) reflection takes place from a polished surface, when the rays travel from a rarer medium to a denser medium.

    

6) Give reasons why:

a) why do stars twinkle ?

b) why the planet is do not Twinkle ?

c) State and explain Snell's law of the reflection of light.

7) What two conditions must be fullfilled for the total internal reflection of light to occur ?

8) What should be the ratio the speed of light through the liquid to the speed through glass so that there is no refraction of light at the boundaries of the glass block when the system is illuminated by light of one colour ?

9) State two advantages of using a right angled prism as a reflector, rather than a plane mirror..

10) Explain briefly what causes the twinkling of stars at night.

11) a) What is meant by refraction ?

b) Express the refractive index n of a medium:

    i) in terms of velocity of light

    ii) in terms angle of incidence i in air and the angle of refraction r in a danser medium.

c) If a ray of light passes from medium I to medium II without any change of direction, what can be said about the refractive indices of these media (angle I is not 0)?

Questions Based On Diagrams

1) Draw a ray diagram to illustrate has a ray of light incidence obliquely on one face of a rectangular glass slab of uniform thickness emerges parallel to its original direction. Mention which pairs of angles are equal.

2) Draw diagram to show the refraction of light from 

a) air to glass glass

b) glass to air.

In each diagram, label the incidence ray, refracted rays, the angle of incidence (i) and the angle of refraction (r).

3) a) Copy the diagram given below and show clearly the path of the ray, through the glass slab, till it emerges out in air. In the diagram, clearly show 

i) angle of incidence 

ii) angle of refraction

iii) angle of emergence 

b) How is angle of incidence related to angle of emergence ?

c) On the diagram clearly show the lateral displacement.

a) The complete labelled diagram is in shown in which i is the angle of incidence, r is the angle of refraction and e is the angle of emergence .

b) Angle of incidence is equal to the angle of emergence

c) lateral displacement is equals to XY

4) Figure shows a point source P inside a water container. Three rays A, B and C starting from P are shown upto the water surface, Show in the diagram the path of these rays after striking the water surface. The critical angle for water air PR is 48°.

5) a) A ray of monochromatic light enters glass PQRS as shown in figure. Complete the path of rays till it emerges from the glass. Critical angle of glass is 42°.

b) Draw a neat diagram of a prismatic periscope.

c) What are the advantages of total internal reflecting prism over plane mirror?

6) a) Copy the following diagram and complete it to show the rays emerging out of the prism B.

b) State the principal used for the completing your ray diagram.

7) By the drawing a diagram show:

 Why does a stick immersed partially obliquely in water appear bent and short?

8) Why a coin placed in water tank appears raised ?

9) Why are not the stars exactly the same position, where they appear to the eye ?

10) Why does a tank filled with water appear shallow?

11) A student puts his pencil into an empty trough. What changes will be observed in appearance of the pencil. When water is poured into the trough ? The student observes the pencil through the water from the position indicated in the diagram.

12) Name the phenomena which accounts for the above stated observation. Complete the diagram showing how the student's eye sees the pencil through the water .

13) During the sunset and sunrise, the Sun is seen even when it is slightly below the horizon. Explain the reason.

Or

Why does the sun appear bigger during sunset or sunrisethe ?

14) Figure shows two rays of light OP and OQ coming from an object at the bottom of a pond, incidence on the water surface.

a) Mark on the diagram:

i) the angle of incidence of ray OP.

ii) the angle of refraction of ray OP

iii) the position of image of the object as seen from above.

A) FILL IN THE BLANKS:

1. When a ray of light of light travelling obliquely in a____ medium, enters a denser medium. It always bends___ the normal. 

2. When a ray of light of light travelling obliquely in a denser medium, enters a_____ medium, it always bends away from the____. 

3. When a ray of light strikes the surface of separations of two optical media at right angles, it__ suffer any______. does 

4. Total internal reflection occurs when a ray of light passes from a ____medium to a____ medium.

5. For total internal reflection angle of incidence in the denser medium should be_____ then critical angle.

6. Sine of critical angle= ___.

7. Critical angle is the angle of the angle of____ for which the angle of_____ is____. 

8. μ = Velocity of light in _____velocity of light in a _____. 

9) sin r= sin i/___ .

10. Angle of deviation is the angle which the____ ray makes with the ___ ray. 

11) The twinkling star is due to_____.

B) STATE whether true or false. Also correct the false statements

1. When a ray of light passes from one medium to another, its direction does not change but the frequency changes.

2. If the angle of incidence is less than Critical Angle, light is not refracted at all when it falls on the surface from a denser medium to a rare rare medium.

3. When a Ray of light travels from a rarer medium to a denser medium, it bends away from the normal.

4. Lateral displacement decreases with the increase in thickness of the medium and with the increase in angle of incidence.

5. The refracted ray inside a prism travels perpendicular to the base if the prism is equilateral.

6. If the refractive index of glass with respect to air is 4/3, the refractive index of air with respect to class will also be 4/3.

7. Refractive index of red light greater than that of violet light.

8. The critical angle for a pair of media is less for red light and more for violet light.

9. A total reflecting prism used to deviate a ray of light through 80° and 180°.

FLOWERING PLANTS (2) O.Q

1) Define a flower.

2) The figure below represents the longitudinal section of a flower.

i) Label the parts 1 to 10.

ii) Name the four whorls of the floral parts of the flower 

iii) Name the male and the female parts.

2) Give the collective name of each of the following in a flower.

a) stamens 

b) carpels 

c) sepals 

d) petals 

3) Distinguish between each of the following pairs:

a) a complete and a incomplete flower 

b) a bract and a bractiole.

c) calyx and epicalyx.

d) a staminate and a pistillate flower 

e) a regular and an irregular flower 

4) State which of the statements are true or false:

a) the stalk of a flower is called Petiole.

b) The function of a flower is only to attract insects.

c) The calyx which is green manufactures food.

d) The pistil and the gynoecium are one and the same.

e) The receptive part of a carpel is the stigma.

f) pollination is the fusion of two pollen grains.

g) seeds are produced by the anthers lobes.

h) The receptacle is the other name for thalamus.

5) Draw labelled diagram to represent 

a) a pistil 

b) a Stamen

6) The diagram below represent the flower and the ploral parts shown separately.

a) What do the diagram A, B, C and D represents ?

b) Label the parts in A, C and D to which the guidelines point.

c) What is the importance of the peculiar adaptation of the shape and the structure of the petals and staminal tube in the flower ?

7) The figure alongside represents the cross-section of an anther. Label the part 1 to 4.

i) State whether it is a male or a female organ.

ii) How are pollen grains usual ejected?

iii) What is the collective name for the organs of this kind ?

iv) How are the pollen grains structurally adapted for pollination and later for fertilization ?

v) Are the contents (1) lodged in part 2 male or female ?

8) What is the name of the stalk which holds a flower up?

9) What is the function of the anther in a flower?

10) What is carpel?

11) What is an ovule?

12) What is inflorescence?

13) Given here are diagrams showing six different types of inflorescence, Name them;

) 

FLOWERING PLANTS (1)

      Showing an angiospermic plant

      

Calyx

• Collection of sepals

• Accessory outermost whorl

• Provide protection to reproductive parts

Corolla

•Collction of petals 

• Accessory whorl inner to calyx

• Brightly coloured, help in pollination 

• Provide protection to reproductive parts.

Androecium

• Collection of stamens 

• Reproductive whorl, produce male gametes 

Gynoecium

• Innermost reproductive part

• Produce female gamete.

Fruit

• Contains seeds

A) Difine:

1) Androecium.

2) Axillary

3) Bud

4) Calyx

5) Capitulum 

6) Carpel

7) Corolla .

8) Disc-floret

9) Gynoecium 

10) Keel

11) Lamina

12) Legume (or pod)

13) Overy

14) Pappus

15) Pedicel

16) Petals 

17) Petiole

18) Ray floret.

19) Receptacle( or thalamus)

20) Root cap

21) Root hair

22) Sepals

23) Stamen

24) Standard 

25) Stigma 

26) Style: 

27) Wing: 

B)

1) Draw a labelled diagram of a flowering plant. 

2) Name the vegetative and reproductive parts of a flowering plant. Which of these are more important to the life of a plant and why ?

3) Name the parts of the embryo which develop into root system and shoot system

4) Give major functions of 

a) roots 

b) Stem

c) Leaf

5)  what is the function of 

a) Sepalas.

b) Petals.

6) Give the collective names of:

a) Petals

b) Sepals

c) Stamens

d) Carpels

7) State the difference between the following :

a) Node and Internode 

b) Fruits and seeds

c) Ray floret and Disc floret

d) Flower and  Influorescence

8)  How is root tip protected ?

9) What are buds? Name the types , location and function of the buds.

C) Name the following:

a) The two parts of a leaf.

b) The accessory parts of a flower.    

c) The essential parts of a flower.    

d) The part of the carpel which encloses ovules.    

e) The fruit found in pea family

f) The stalk of a flower.  

D) Match column

Column I         Column- II 

1) Root        a) female reproductive part

2) Sepalas  b) manufacturers food 

3) petals     c) fruit

4) androco  d) protects the floral parts in bud

5) ovary      e) attract the insects for pollination

6) Ovule     f) male reproductive part

7) Stem     g) seed

8) Leaf.     h) absorbs water and minerals 

9) gynoecium i) holds the leaves and flowers 

E) Fill in the blanks:

1) The main function of the root system is____ and ___.

2) The part of a flower which are essential for the reproduction include___ and ____.

3) The part of the stamens in which pollen grains are produced is ____.

4) The different floral whorls in a flower from outside to inside are____ , ____, ____ and ____.

1) Fixation, absorption of water and minerals 

F) Complete the following by selecting the correct word :

1) Fruit is the ripened ____. (Ovary/bud/stamen)

2) Calyx and corolla constitute the _____ in a flower. (Essential whorls/accessory whorls/receptacles)

3) _____ is necessary for fertilization. (Calyx/bud/pollination)

4) Modified hairy calyx in sunflower is called _____. (Pappus/keel/ray floret)

G) Mention whether the following statements are true or false:

1) Egg cell is present inside the ovule . 

2) In pea plant, the petals are equal in size .   

3) Two kinds of flowers are present in sunflower.   

4) Bell-shaped corolla is found in flowers of pea plant.   

REVISION - SCIENCE -TEST - IX(2024/25)

16/11/24

POLLINATION 

1) Define pollination.

2) How is self pollination different from cross pollination mention three advantages and to disadvantages of cross pollination.

3) Mention four characteristics of wind pollinated flowers.

4) What is meant by self pollination ? Mention its one disadvantages.

5) Explain the term fertilization.

6) What is double fertilization.

7) The diagram alongside shows the internal structure of gynoecium . Name the parts number 1 to 9.

8) The following sentences describe the changes occurring in the flower after fertilization.

Fill in the blanks by selecting suitable words given here. (Ovary, stamens , seeds, ovules, petals, calyx, stigma, fruit)

a) The ______, ____, ____, style and ____ wither and generally fall off.

b) The ____may either fall off or may remain intact in a dried form.

c) The ____enlargest to form a ____, the ovarian wall forming the fruit wall.

d) ____ become the seeds.

9) With the help of suitable diagrams, briefly describe the process of fertilization.

10) Mention the fate of floral parts after fertilization.

11) Give appropriate terms for the following :

a) A flower which contains only stamens.

b) A flower which contains only carpels.

c) A condition in which sepals are fused.

d) A condition in which petals are free.

e) Arrangement of flowers on the twig.

f) Transference of pollen grains from the anther to the stigma.

12) Explain briefly the idea contained in the following statements:

a) Certain plants have large, brightly coloured flowers which emit scent and produce nectar.

b) Some plants have small flowers will long hanging stamens , in which anthers are loosely attached to the filaments, and they produce pollen in large quantities.

c) Both male and female flowers are borne on the same plant, and the anthers and stigma mature at the same time.

13) Given in the diagram of the hydrophilous plant.

a) Label the parts 1 to 4.

b) Label the two plants A and B as a male plant and female plant.

c) Mention two characteristics of the pollen grains.

26/10/24

PLANT TISSUE 

A) State whether the following are true or false:

1) The cells of a tissue are similar in structure but different and function.

2) Apical meristem is responsible for the elongation of the stem.

3) Meristem tissues can be called as growth tissues .

4) The meristematic cells are thick-walled.

5) The shoot apex contains lateral meristem.

6) Xylem and phloem are supporting tissues.

7) Phloem is made up of mainly dead cells.

8) Xylem helps to transport water in upward direction.

9) Phloem is present outside the xylem tissue.

10) Xylem and phloem consist of living cells.

11) Permanent tissue have definite form in size.

12) Meristematic tissue are also called growth tissues .

13) Intercalary meristem increases the diameter of the plant parts.

14) Parenchyma serves as the packing material in the body of an organism.

15) Sclerenchyma tissue is composed of live cells without any spaces in between.

16) Phloem is a living tissue while xylem is a dead tissue.

B) Name the simple permanent tissue which

a) is composed of thin-walled cells .

b) comprises dead cells 

c) has cells with large spaces in between.

d) is made up of cells whose cell wall is thickened at corners.

e) is present in the hard coverings of nuts.

C) Choose the correct option.

1) The thin-walled living cells found in the soft parts of a plant are 

a) parenchyma  b) collenchyma c) xylem d) phloem 

2) The plant tissue that helps in transportation of water is 

a) xylem b) phloem  c) sclerenchyma d) parenchyma

3) In potato, starch is stored in the 

a) phloem b) parenchyma c) sclerenchyma d) chlorenchyma 

4) Lignin is present in the cell walls of 

a) sclerenchyma b) parenchyma c) chlorenchyma d) collenchyma 

5) The cells of sclerenchyma are 

a) living and thin-walled 

b) living and thick-walled

c) dead and thin-walled 

d) dead and thick-walled 

D) Fill in the blanks with missing words.

1) Potato tubers store starch in_____ cells.

2) ____acts as cement and makes sclerenchyma hard.

3) Parenchyma containing chloroplasts is known as____

4) ____ tissue is responsible for the elongation of the stem .

5) The increase in the diameter the root occurs by the division of___ tissue.

E) Match the following:

Column A

1) Lignin deposit 

2) Manufacture of food 

3) Transportation of food

4) Base of leaves

5) Thickened corners 

Column B

a) Collenchyma 

b) intercalary meristem

c) Sclerenchyma 

d) Chlorenchyma 

e) Phloem 

F) Pick the odd one out :

1) Meristem , parenchyma, apical, intercalary 

2) Xylem, vascular, food, phloem.

3) Sclerenchyma , lignin, coconut, parenchyma.

4) Flexible , tissue, thickened corners , leaf stalk,  thin-walled 

G) Name the type of the tissue found:

1) At the top of the plant roots.

2) At the base of the leaves.

3) On the outer side of vascular bundle.

4) In the inner side of The vuscular bundle.

5) In the leaf stalks.

6) In the hard covering of seeds. 

H) Identify the following tissue:

1) plyant tissue consisting of cells with thickened corners.

2) Permanent plant issue with intercellular spaces.

3) Plant tissue that has lost its stability to divide.

4) Simple permanent plant tissue consisting of cells with thick cell walls.

5) Tissue responsible for the transportation of water in plants.

I) Observe the figure carefully and answer the questions given below :

a) identify the tissue.

b) Write any two features by which you identified this tissue.

c) Where will you find this tissue ?

d) Give any two functions of this tissue.

e)  Name two more tissues which have similar structure and function

16/8/24

Biology test 

TEETH 

1) Give the technical names for the following types of teeth in humans(on each side, in each jaw)

a) The three last grinders 

b) The broad temporary (deciduous) grinding teeth 

c) The pointed sharp cutting teeth.

d) The pointed tooth for holding and tearing.

2) Name the following parts of a tooth.

a) Part exposed above the gum.

b) The hard substance making the covering of the tooth.

c) The soft connective tissue contained in the central space of the tooth.

d) Bone like structure fixing the root in position.

e) Slight constriction between the root and the crown.

3) What is the dental formula of a normal human adult.

4) Study the diagram given below and then answer the following questions:

a) Name the parts labelled 1,2,3,4,5 and 6.

b) Identify the tooth and give a reason to support your answer.

c) Describe the structure of the part labelled 3

d) Give the total number of the type of tooth mentioned in 1 above, in the mouth of an adult and state its function.

5) Study the following dental formula and then answer the questions that follow:

i 3/4    c 0/0    pm 0/1    m 1/1

a) What is the total number of teeth in the 

i) upper jaw 

ii) lower jaw?

b) State the total number of teeth present in the dentition 

c) Give the dental formula of an adult human being.

SECTION - A (Attempt all)

Question -1

a) Choose the correct word from the choice in bracket.      (5)

   i) A covalent molecule of oxygen contains [¹⁶₈O] contains ____ (1/2/3/4) electrons in the outer shell of each of the oxygen atoms, which are not involved in sharing.

  ii) Molecular weight of oxygen is 32 g i.e., 1 molecule of oxygen is____ (64/16/32)  times as heavy as 1/12th the mass of the carbon atom  (C¹²).

  iii) Efflorescent salt on exposure to the atmosphere, change from____ (amorphous to crystallization/ crystalline to amorphous) state.

  iv) Temporary hardness is due to____(soluble/ insoluble) calcium & magnesium bicarbonate in water.

  v) In double decomposition reactions between two compounds - base & acid - to give salt & water, there is an interchange of_____ (ions/ radicals/ molecules).

b) Identify the types of reactions A to E, by matching them with the reaction (i) to (v).  (5)

A: Displacement reaction B: Thermal dissociation C: Reduction reaction D: Double decomposition reaction E: Photochemical reaction 

i) 4AgBr ---> 2Ag₂Br + Br₂

ii) Mg + 2HCl(Dil)------> MgCl₂+ H₂

iii) Cu(OH)₂ + H₂SO₄(Dil)---> CuSO₄ + 2H₂O.

iv) NH₄Cl <=> NH₃ + HCl

v) 2FeCl₃ + H₂S ----> 2FeCl₂ + 2HCl + S

c) Match the names of compound interest Column A with their correct formulas for column B                 (5)

  Column A 

i) Iron(III) Chloride 

ii) Iron(III) oxide

iii) iron (II) chloride

iv) iron (III) sulphate

v) iron(III )sulphide

   Column -B 

a) FeCl₂

b) Fe₃I₄

c) Fe₂O₃

d) FeCl₃

e) FeO

f) FeS

g) FeSO₄

h) Fe₂S₃

i) FeCl

j) FeS₂

k) Fe₂(SO₄)₃

d) Give reasons for the following:        (2)

i) A saturated solution can be converted to an unsaturated solution by heating the saturated solutions slowly .

ii) Both precipitation and neutralization reactions are considered as a double decomposition reactions.

e) Choose the correct word or letter from the brackets to complete the sentence and write only that down as the answer.         (2)

i) Ammonium sulphate is an example of a/an_____(hydrous /anhydrous/ crystalline) salt.

ii) The relative atomic mass of an element expressed in grams is known as- ____(a.m.u/ gram atom/ gram molecular mass).

f) Give balanced equation for the following conversations.       (5)

i) zinc to sodium zincate.

ii) ozone to two molecules of Oxygen gas.

iii) hydrogen to ammonia.

iv) sulphur trioxide to sulphuric acid- a component of acid rain.

v) Iron to Iron(II ) chloride.

 SECTION B 

Question -2

Select the correct word from the words in bracket to complete each statement.    

     Any two (2)

i) If boiled water after filtering, lathers with soap, it is said to be sample of____( permanent/temporary) hard water.

ii) The formula of the phosphate radical is _____(PO₃³⁻/PO₄³⁻/PO₄²⁻).

iii) Components in a compound_____ (retained/do not retain) their original properties.

Question -3   any two (2)

i) Draw the atomic orbit structure of the formation of:

   a) electrovalent compound- sodium chloride (Na=11, Cl=17)

   b) covalent molecule - nitrogen (N=7)

ii) Name - a covalent molecules formed from two different elements, having a three single covalent bonds.

iii) Differentiate between-

 Shared pair and loan pair of electrons with reference to -

Covalent molecule - water (H= 1, O= 8)

Question - 4 any two (2)

A) Choose the letter corresponding to the correct answer from the choice A, B, C or D given below in each case.

i) The salt which is efflorescent and the residue after exposure is an anhydrate.

 a) washing soda b) calcium chloride c) Glauber's salt d) iron(III) chloride

ii) The salt whose solubility in water decreases with rise in temperature.

a) calcium sulphate  b) sodium nitrate c) potassium nitrate  d) ammonium chloride

iii) The anhydrous salt which changes colour on reaction with water.

a) calcium sulphate b) sodium sulphate c) Cobalt chloride d) calcium chloride 

Question - 5 Any two (2)

Select the correct answer from the words in brackets.

i) The formation of hydrogen and oxygen from acidified water is an example a/an

  (photochemical reaction, electrochemical reaction, endothermic reaction)

ii) A reaction in which Mercury (II) oxide, breaks up on heating to give Mercury and oxygen is example of -

(thermal dissociation, thermal decomposition, displacement reaction)

iii) A neutralization reaction between lead hydroxide and nitric acid, results in formation of a/an -

(Soluble salt, insoluble salt)

Question - 6

A) Give balanced equations for the following direct combination reactions -between an acidic oxide and water to give the acids given below.     (Any two (2))

  i) sulphurous acid

  ii) phosphoric acid 

  iii) carbonic acid 

B) Underline the reduced product in each of the following reactions : Any one (1)

i) Cl₂ + 2H₂O + SO₂ --> 2HCl + H₂SO₄.

ii) Br₂ + H₂S ---> S + 2HBr.

C) Any one (2)

 i) Calculate the percentage by weight of chromium in potassium dichromate. (K= 39, Cr= 52, O= 16)

ii) Calculate the relative molecular mass of CH₂O. (C= 12, H= 1, O= 16).

Question -7 Any three (3)

A) Give balanced equation for the following:

i) a direct combination reaction-- involving Phosphorus and a neutral gas.

ii) A direct combination reaction- involving pressure as one of the conditions of the reaction.

iii) A reaction of conversion of - calcium sulphate in permanent hard water to calcium carbonate using washing soda.

iv)  conversion of zinc nitrate to insoluble zinc carbonate by a double composition reaction.

A) Match different types of chemical reactions in column II with the meaning of the type of reactions in colum I .

Column- I

1) A chemical reaction in which two or more elements or compounds react to form one new compound as a product.

2) A chemical reaction in which chemical compound decomposes or split up into two or more simpler substances. It is generally brought about by heat.

3) A chemical reaction which takes place when an element (or radical) has replaced another element in a compound.

4) A chemical reaction in which two reactants are both decomposed to form new substances by exchanging their radicals.

5) A chemical reaction which employs a catalyst to alter the rate of a reaction.

6) A chemical reaction in which the products formed react together to form the original reactants depending on the conditions of the reaction.

7) A reaction in which a substances dissociates into two or more simpler substances on application of heat and is a reversible reaction.

8) A reaction which involves addition of oxygen or electronegative element or removal of hydrogen or electropositive elements.

9) A reaction which involves addition of hydrogen or electropositive element or removal of oxygen or electronegative element.

10) A chemical reaction which proceeds with evaluation of heat energy.

11) A chemical reaction which proceeds with absorption of heat energy.

12) A chemical reaction which proceeds with absorption of light energy.

Column II 

a) Double decomposition 

b) Exothermic reaction 

c) Reversible reaction 

d) Displacement reaction 

e) Combination or synthesis 

f) Decomposition reaction 

g) Thermal dissociation

h) Endothermic reaction 

i) Catalytic reaction

j) Oxidation reaction 

k) Photochemical reaction 

l) Reduction reaction.

B) State the type of reaction/s to which each of the following belongs 

1) Addition of a zinc to copper sulphate solution.

2) Heat on lead nitrate crystals .

3) Preparation of oxygen from Potassium chlorate.

4) Conversion of ferrous chloride to ferrous chloride is using chlorine.

5) Formation of ammonia from nitrogen and hydrogen.

6) Liberation of hydrogen at the cathode from acidified water.

7) Manufacture of glucose by green plants.

8) Formation of nitric oxide from nitrogen and oxygen.

9) Addition of zinc to dilute sulphuric acid.

10) NH₄Cl <=> NH₃ + HCl.

11) 2KNO₃ ∆ ---> 2KNO₂ + O₂.

                   H₃PO₄

12) 2H₂O₂ -------->  2H₂O+ O₂.

13) PbBr₂ ----> Pb²⁺ + Br¹⁻(ions).

14) 2HgO ∆ ---> 2Hg + O₂.

15) N₂O₄ <==∆=> 2NO₂.

16) AgNO₃ + KCl ---> AgCl + KNO₃.

17) Fe + S ---> FeS.

                     ₛᵤₙₗᵢghₜ

18) H₂ + Cl₂ -------> 2HCl.

19) C + H₂O ---> CO + H₂ - ∆.

20) Cl₂ + 2KI ----> 2KCl + I₂.

21) 3Fe + 4H₂O <=∆=> Fe₃O₄ + 4H₂.

22) 2Cu + O₂ ---> 2CuO.

23) Fe₂O₃ + 2Al ----> Al₂O₃ + 2Fe.

24) KNO₃ + H₂SO₄ ---> HNO₃ + KHSO₄.

25) 2FeCk₂ + Cl₂ ----> 2FeCl₃.

26) Fe + H₂SO₄ ---> FeSO₄ + H₂.

27) SO₂ + Cl₂ ---> SO₂Cl₂.

28) 3Ca + N₂ ----> Ca₃N₂.

29) CuSO₄ + Fe ---> FeSO₄ + Cu.

30) 4HNO₃ ---> 2H₂O + 4NO₂ + O₂.

C) Oxidation and reduction reactions are generally termed as a redox reactions . In the examples given below underline the oxidised product or reduced product in the respective reactions. The circled substance is the oxidizing or reducing agent respectively.

  oxidation reactions

1) Cu₂ + O₂ ---> 2CuO.

2) H₂S + Cl₂ ---> S + 2HCl.

3) 2FeCl₂ + Cl₂ --> 2FeCl₃.

4) SO₂ + H₂O + Cl₂ ----> H₂SO₄ + 2HCl.

5) H₂S + 2FeCl₃ ---> 2FeCl₂ + 2HCl + S.

6) Zn + H₂SO₄ ---> ZnSO₄ + H₂.

7) Fe + S  ---> FeS.

8) 2Mg + SO₂ ---> 2MgO + S.

9) 2H₂S + SO₂ ---> 3S + 2H₂O.

10) S + 2H₂SO₄ --->  3SO₂ + 2H₂O.

  Reduction reactions 

1) CuO + H₂ ---> Cu + H₂O.

2) Br₂ + H₂S  -----> 2HBr + S.

3) 2FeCl₃ + H₂S  ---> 2FeCl₂ + 2HCl + S.

4) 2HgCl₂ + SnCl₂ ---> Hg₂Cl₂ + SnCl₄.

5) 2FeCl₃ + SO₂ + 2H₂O ----> 2FeCl₂ + 2HCl + H₂SO₄.

6) Fe₂(SO₄)₃ + 2H₂O + SO₂ ---> 2FeSO₄ + 2H₂SO₄.

7) Cl₂ + 2H₂O + SO₂ ---> 2HCl + H₂SO₄.

8) 2HNO₃ + SO₂ ---> 2NO₂ + H₂SO₄.

9) 2KMnO₄ + 2H₂O + 5SO₂ ---> 2MnSO₄ + K₂SO₄ + 2H₂SO₄.

10) K₂Cr₂O₇ + H₂SO₄ + 3SO₂ ----> Cr₂(SO₄)₃ + K₂SO₄ + H₂O.

D) Name the following:

1) A coloured gaseous oxidising agent.

2) A liquid oxidising agent with on thermal decomposition in presence of a catalyst liberates oxygen.

3) A gaseous reducing agent containing oxygen.

4) An acid other than nitric and Sulphuric Acid which is an oxidising agent.

5) A gaseous reducing agent neutral in nature other than carbon monoxide.

6) An oxidizing agent which liberates chlorine on heating with concentric hydrochloric acid.

7) Two neutral gases which react to give a basic gas and the reaction is exothermic.

8) Two neutral gases which react to give a neutral oxide and the reaction is exothermic.

9) A substance which decomposes by absorption of sound energy.

10) Two substances which react explosively on close physical contact.