Tuesday, 21 February 2023

COMPACT QUESTIONS (CHEMISTRY) For - X

MODERN PERIODIC TABLE 

1) State the modern periodic law.

2) Complete the statement- Modern Periodic Table arranges elements in increasing order of____ in____ horizontal rows called a periods and ___vertical columns called____. The most reactive metals are placed in group____ and elements with eight valence electrons in group_____.

PERIODS IN THE MODERN PERIODIC TABLE

3) The period which is called a short period is - period 1, period 2, period 3, period 4, period 5, period 6, period 7.

4) The number of elements in period 1, period 2 and period 3 respectively are -- 2,2,8; 1,6,8; 2,8,8; 8,8,8.

5) Arrange the elements of period 2 in ascending order of atomic numbers-- N, B, Be, F, C, O, Ne, Li.

6) Arrange the elements of period 3 in ascending order of atomic numbers -- Mg, Si, S, Cl, P, Al, Na, Ar.

7) The chloride of the element belonging to period 3, group______ exists in both liquid and solid state.

8) The Hydroxide of the element belonging to period____, group I and group III shows strong basic and amphoteric character respectively.

9) Complete the statement-- property trends of elements from left to right in a period show that elements of the same period have ____number of electron shells in which the valence electron____ by one across period. A transition from ____ to____ character is seen.

10) If an element X has atomic number 16, to which period and group of the Periodic Table does it belong.

11) An element Y has atomic number 10. State its valency and the group to which it belongs.

12) An element Z has electronic configuration 2,8,2. State the type of bonding and the character of its oxide.

GROUPS IN THE MODERN PERIODIC TABLE

13) State the group number of the element X  2,8 ,18, 8, 1.

14) Complete the statement-- property trends of elements on moving down in a group of periodic table, show that elements of the same group have____ valene electrons, and the electron shells ____ progressively by one down a group. Elements in the same group have_____ chemical properties.

15) Complete the statement--- Lithium, Sodium and potassium are___ metals belonging to group____ and fluorine, chlorine and bromine are _____ belonging to group_____. Chlorine is a strong____ agent and its hydride is_____ in nature.

16) State four dissimalirities in properties of alkali metals and halogens.

PERIODIC PROPERTIES & PERIODIC TRENDS IN PROPERTIES

17) Characteristic properties of elements arranged in the Periodic Tables are repeated at regular intervals. What are these properties called. What does the terms regular intervals signify.

18) State which of the following is a periodic property---solubility, malleability, nature of oxide, density, combustibility, conductivity, melting and boiling point.

19) The amount of energy required to remove an electron from the outermost shell of an isolated gaseous atom is called its-- electron affinity, Electronegativity, Ionization potential.

20) State the relation between atomic number and atomic mass of a light element like sodium(atomic number 11, mass number 23). Is the element stable or unstable. Give reasons.

21) Complete the statement using the words 'increases or decreases' at the appropriate place.
 The trends in periodic properties across a period from left to right show that the atomic size of an element____, Ionization potential_____and Electronegativity____. The trends in periodic properties down a group show that atomic size of an element____, electronaffinity______ electronegativity______, and metallic character of an element_____.

22) With reference nuclear charge of an atom and number of shells in the atom give a reason why the atomic size decreases across a period from left to right.

23) State the factors from the following which affect Ionization potential-- Number of shells in an atom, atomic size of an atom, nuclear charge of an atom, metallic or nonmetallic character of an atom.

24) Complete the statement-- atoms with the large atomic size and low ionisation potential value tend to____(gains/loose) electrons.

25) Arrange the elements-- S, P, Si, Cl, in increasing order of electronegativity.

26) Arrange the elements--- O, F and Ne in decreasing Ionization potential.

27) State which element has a higher electon affinity-- Boron or Carbon.

28) State which element has a more non metallic character-- aluminium, Silicon or phosphorus.

CHEMICAL BONDING 

1) Complete the statement--The ____ which acts between two or more atoms to hold them together as a stable molecule is called____ bond and the concept ________.

2) Complete the statement-- Helium has  a stable____ arrangement to while neon and organ have a stable _______ arrangements.(octate/duplet)

ELECTROVALENT BONDING- ELECTROVALENT COMPOUNDS

3) Differentiate between
A) electropositive valency and Electronegative valency.
B) 'X' and 'X²⁺'
C) The conversion: A - 1e⁻¹ --> A¹⁺ and A + 1e⁻ --> A¹⁻

4)  In the formation of calcium oxide from calcium atom and oxygen atom, the calcium ion in the compound calcium oxide after combination shows ____ (Ca¹⁺/Ca²⁺/Ca²⁻) valency.

5) In the formation of electrovalent compound -- magnesium chloride, the correct ionic equation is ____
(Mg + Cl --> Mg²⁺ 2Cl¹⁻/Mg + 2Cl --> Mg²⁺ Cl¹⁻/Mg + 2Cl --> Mg²⁺ 2Cl¹⁻ )

COVALENT BONDING-- COVALENT COMPOUNDS

6) State which of the following has two shared pairs of electrons between them during formation of a covalent compound.
('X' and 'X' electronic configuration 2,6/ 'Y' and 'Y' electronic configuration 2,7/ 'Z' and 'Z' electronic configuration 2,5)

7) State which of the following pertain to polar covalent compounds ---
A) shared pair of electrons are equally distributed between the two atoms.

B) the more electronegative atom attracts the electron pairs toward it.

C) the molecules is electrically neutral.

D) charge separation takes place in the molecule.

E) are formed generally between dissimilar atoms.

8) State which of the following has
A) two single covalent bonds.
B) four single covalent bonds.
C) three single covalent bonds.
D) One Double covalent bond.
E) one triple covalent bond in its molecule--- hydrogen, chlorine, nitrogen, Methane, oxygen, water, Ammonia, carbon tetrachloride.

COVALENT COMPOUNDS -- CO-ORDINATE COVALENCY

9) Complete the statement -- Ammonia molecule has ____lone pair of electrons not shared with any other atom and____ molecule has two lone pairs of which one remains unshared during formation of the hydronium ion.

PROPERTIES OF ELECTROVALENT AND COVALENT COMPOUNDS

10) Give a reason why --
A) NaCl is a hard solid having a high melting point.

B) Water dissolves sodium chloride but an organic solvent does not.


ACIDS, BASES AND SALTS

ACIDS AND BASES

1) Name
A) an organic oxyacid
B) an inorganic Hydracid.

2) Name the ions present in an aqueous solution of hydrogen chloride.

3) Name a base insoluble in excess of Ammonium hydroxide solution.

4) Give a reason why dilute sulphuric acid is considered a strong acid while carbonic acid is a weak acid.

5) What does the strength of an alkali depend on.

6) Differentiate between the terms-- Basicity of acid and acidity of bases.

7) State which of the following has acidity equal to two -- Sulphuric acid, carbonic acid, zinc Hydroxide, Ammonium hydroxide.

8) Name a base obtained from iron(III) sulphate and caustic soda.

9) State two chemical properties to prove that a given solution contains
A) hydrogen ions.
B) hydroxyl ions.

10) State a reaction in which a less volatile base displaces a more volatile base.

USES OF ACIDS AND BASES

11) Name a base used in bleaching powder preparation and an acid used in cooking.

REACTIONS OF ACIDS WITH BASES

12) 'Acids reacts with the bases to give salt and water only'. Rewrite the defination of neutralization as per the ionic theory with an ionic equation.

INDICATORS

13) Indicators dissociate in solution producing ions and associated molecules. State on what is the colour of the ions produced dependant on.

14) Compared to water, state the pH of a solution which liberates hydrogen on addition of an active metal to it and of a solution which reacts with a metallic salt to give a blue participate of copper Hydroxide.

15) What is a Litmus indicator. How does it differ from a universal indicator.


ANALYTICAL CHEMISTRY

1) State the colours of the following salts:-
A) Copper (II) sulphate.
B) Iron(III) sulphate.
C) Chromium chloride.
D)  Magnesium nitrate.
E) Aluminium phosphate.
F) Potassium permanganate.
G) Potassium dichromate.

2) Name a salt which if reacted with Sodium Hydroxide will give :-
A) A dirty green precipitate.
B) A gelatinous white precipitate soluble in excess.
C) A chalky white precipitate soluble in access.

3) Name is salt which if reacted with Ammonium hydroxide will give:-
A) A pale blue precipitate soluble in excess to give a deep blue solution.
B) A chalky white precipitate insoluble in excess
C) A reddish brown precipitate.

4) Give balanced equations for formation of sodium zincate from
A) A metal
B) A metal oxide
C) A metal hydroxide.

ELECTROLYSIS

TERMS INVOLVED IN ELECTROLYSIS

1) State which of the following are non electrolytes-- dilute nitric, concentric sulphuric acid, methanol, Ammonium hydroxide solution, carbon disulphide, acidicfied water, ethylene.

2) State which of the following are weak electrolytes --Acetic Acid, molten lead Bromide, Sodium Acetate, potassium carbonate, Aq. Zing nitrate.

3) Complete the statement--  Anions migrate to the _____and are discharged at it by____ electros to the respective electrode and get ____to neutral atoms.

MECHANISM OF ELECTROLYSIS

4) State which of the following undergoes electrolytic dissociation--- aqueous copper chloride, hydrogen chloride , Ammonia.

5) In which case i.e., electrolytic or metallic conduction does flow of electricity takes place by flow of irons.

ELECTRLYTES, ELECTROCHEMICAL SERIES, SELECTIVE DISCHARGE

6) State which of the following i e., Acids, bases or salts furnish positive ions other than hydrogen ions and negative ions other than hydroxyl ions in aqueous solution state.
       
7) State which ions Ag¹⁺ or H¹⁺ is discharged at the cathode after migration to it 

EXAMPLE OF ELECTROLYSIS

8) The product obtained at the cathode during electrolysis of molten lead bromide is --- lead Ion, bromine vapours, lead metal.

9) State the electrode used during electrolysis of acidified water.

10) How are OH¹⁻ ions formed at the anode converted to O₂ gas at the anode during electrolysis of acidified water.

11) The electrode reaction: Cu - 2e⁻ --> Cu²⁺ takes place at the anode/cathode during electrolysis of aq. CuSO₄ using copper electrodes.

APPLICATION OF ELECTROLYSIS

12) Give a reason why the block of silver is made the anode during electroplating of an article with silver.

13) Name the positive ions present in aqueous sodium silver cyanide on electrolytic dissociation.

14) Name the cathode used during electrorefining of impure silver.

15) Give a reason why zinc is refined by electrolysis but aluminium is not.

16) State which of the following metals are extracted from their fused salts by electrolysis-- iron, copper, magnesium, sodium, silver, lead.

METALLURGY

INTRODUCTION- DEFINITION

1) An element X is a metal. State which of the following points of definition does it correlate to --
A) ionizes by electron gain.
B) is an electron donor.
C) forms cations in solution on Ionization.
D) has a valency which relates to the number of electrons gained per atom.

POSITION OF METAL IN THE MODERN PERIODIC TABLE

2) State which of the following statements are true--
A) alkali metals are present in group IA of the periodic table.
B) alkaline earth metals are heavy electropositive metals in group IA.
C) Lanthanide series form a part of Transmission elements.
D) halogens are present in group VIIA and are highly Electronegative non metals.

CHARACTERISTIC PROPERTIES OF METALS

3)  Give a reason why --
A) alkali metals are highly electropositive metals while alkaline earth metals are comparatively less electropositive metals.
B) non metals are placed on the right of the periodic table and not on the extreme left.
C) Aluminium is weekly electropositive while sodium is highly electropositive.

COMPARISON OF METALS AND NON METALS

4) State which metallic property shown by the non metallic --grapite, and iodine.

5) State which non metallic properties are shown by the metals-- Sodium, Potassium and mercury.

6) State which of the following are good reducing agents-- lead dioxide, sodium, Coke, sulphur, calcium, hydrochloric acid, concentrate nitric acid.

7) State which of the following are acidic oxides-- carbon monoxide, carbon dioxide, nitrous oxide, Sulphur Dioxide, lead(II) oxide.

8) Give a reason why metals are--
A) electropositive in nature.
B) good reducing agents.
C) liberate hydrogen on reaction with dilute acids.
D) form chlorides, electrovalent in nature.

ACTIVITY SERIES

9) Explain the statement --extraction of metal from it's Ore involves a reduction process.

10) State which of the following metallic oxides are reduced to their metals by reducing agents --Sodium oxide, lead(II) oxide, Silver oxide, iron(III) oxide, Magnesium oxide.

11) Name a metal carbonate soluble in water and stable to heat.

12) Name a metal carbonate which leaves a metallic residue on heating.

13) State which of the following metallic hydroxide are soluble in water-- potassium hydroxide, magnesium hydroxide, copper hydroxide.

OCCURRENCE OF METALS

14) Name a halide which contains the metals Sodium and Aluminium in the combined form.

15) Which of the following compounds contains the metal zinc in the combined form --  siderite, Calamine, zincite, fluorspar, galena.

TERMS USED IN METALLURGY

16) Give a reason why a metal is extracted from its ore but not from its minerals.

  
HYDROCHLORIC ACID

1) State which of the following gases would show back suction when dissolved in water to prepare an aqueous solution of the same -- Hydrogen chloride gas, chlorine, ammonia, sulphur dioxide.

PROPERTIES OF HYDROCHLORIC ACID

2) State which of the following ions imparts acidic properties to an aqueous solution of hydrochloric acid-- hydroxyl ions, Hydrogen ions, hydronium ions.

3) An aqueous solution of hydrogen chloride liberates carbon dioxide on reaction with sodium carbonate but a solution of hydrogen chloride in an organic solvent does not. Give reasons.

4) Name two metallic nitrates which react with dilute hydrochloric acid to give white precipitate. Give a reason why copper nitrate is not one of them.

5) In the reaction of preparation of chlorine from manganese dioxide and conc. hydrochloric acid, State the function of hydrochloric acid.

6) Aqua regia is a mixture of one of conc nitric acid and three parts of conc  hydrochloric acid. State which of the two acids is oxidised to chlorine.

TESTS FOR HYDROCHLORIC ACID

7) State the solubility of the white precipitate in liquor ammonia and dilute nitric acid,  the precipitate which is obtained from reaction between silver nitrate solution and dil  hydrochloric acid.

8) How does the reaction of heat on conc. Hydrochloric acid with manganese dioxide serve as a test for hydrochloric acid and also prove the presence of chlorine in the acid. Give a reason why addition of copper hydrochloric acid but addition of zinc to the same does.

USES OF HYDROCHLORIC ACID

9) State a common use of hydrochloric, sulphuric and nitric acid.

10) Give a reason why hydrochloric acid is used during galvanising process.


AMMONIA

INTRODUCTION

1) State an importance source of ammonia other than Ammonical liquor.

2) Give a reason why ammonia is present in traces in atmosphere.

PREPARATION OF AMMONIA

3) Name the alkali which reacts with sal ammoniac in the laboratory preparation of ammonia.

4) Sodium Hydroxide can be used to distinguish between ammonium salt and sodium salt. Give reasons.

5) Calcium oxide can be used as a drying agent for Ammonia but Phosphorus pentoxide is not used for the same. Give reasons.

6) Name a gas other than Ammonia which lighter than air.

7) Name the solution added to a nitride of a trivalent metal to liberate Ammonia.

8) State the ratio of Nitrogen to hidrogen in the manufacturer of ammonia by Haber's process.

9) State two physical properties of ammonia which can be put to application to separate Ammonia from a mixture of ammonia, nitrogen and hydrogen.

PROPERTIES OF AMMONIA

10) Name the product obtained when ammonia undergoes catalytic oxidation, which is not obtained when ammonia burns in oxygen.

11) Give a reason why liquor ammonia is considered as a solution containing hydroxyl ions.

12) State two methods of obtaining ammonium salts from ammonia.

13) Ammonium Hydroxide is used for identifying positive radicals or cations but Calcium Hydroxide is not used for the same.

14) Which of the following Hydroxides are soluble in excess of Ammonium hydroxide -- Copper Hydroxide, Lead Hydroxide, Zinc Hydroxide.

15) State the substance from the flowing which reacts with ammonia liberating Nitrogen -- Oxygen, chlorine, copper(II) oxide, nitric oxide.

TESTS FOR AMMONIA

16) Name a solution of complex salt which changes colour when ammonia is bubble through it.

17) Give a reason why passage of ammonia through copper sulphate solution serves as a test for Ammonia but through sodium sulphate solution does not.

USES OF AMMONIA

18) State which of the following ammonium compounds is used in smelling salts-- ammonium carbonate, ammonium chloride, Ammonium Sulphate.

19) Name an ammonium salt used as a fertilizer and as an explosive.

20) State which of the following acids are prepared from Ammonia --sulphuric acid, nitric acid, nitrous acid, hydrochloric acid.

21) State three properties of liquid Ammonia which render it useful as refrigerant.

NITRIC ACID

INTRODUCTION

1) Name two different acids present in acid rain giving reasons for their presence.

2) How is nitrogen of the air converted to 
A) a neutral oxide 
B) an acidic oxide 
C) an acid.

PREPARATION OF NITRIC ACID

3) State which of the following salts reacted with concentric sulphuric acid during the laboratory preparation of nitric acid -- Calcium nitrate, Sodium nitrate, Potassium nitrate, zinc nitrate.

4) Give a reason why the normal Salt formed during laboratory preparation of nitric acid, sticks to the glass and is difficult to remove.

5) State which of the following would remove the yellowish brown tinge from nitric acid -- Carbon dioxide, Sulphur dioxide, Water, Hydrogen.

6) State the ratio of ammonia to air in the manufacture of nitric acid by Oswald's process.

7) State which gas would be liberated if copper is added to the acid obtained from Oswald's process.

PROPERTIES OF NITRIC ACID

8) State which of the following forms a constant boiling mixture-- dilute hydrochloric acid, dilute nitric acid, Aq. Hydrogen sulphide solution.

9) State the monobasic acid from the following -- hydrochloric acid, nitric acid, acetic acid.

10) State the oxidised product from the following formed when concentric nitric acid reacts with Sulphur dioxide, sulphur, sulphuric acid.

11) Cold very dilute nitric acid liberates hydrogen reaction with magnesium but not on reaction with lead. Give reasons.

12) State which of the following metals are rendered passive on reaction with conc. Nitric acid-- zinc, lead, iron, almunium.

14) What do you see when concentric nitric acid is added to an alcohol.

TESTS FOR NITRIC ACID

15) State the difference in observation and heating concentric nitric acid alone and when heated with copper turnings.

16) State which of the following is the oxidizing agent in the brown ring test for nitric acid-- iron(II) sulphate, concentric sulphuric acid, dil. nitric acid.

USES OF NITRIC ACID

17) Name an explosive prepared from nitric acid.

18) State which of the following is nitrates is used in gun powder --- Ammonium Nitrate, zinc nitrate, potassium nitrate.

19) Give a reason why nitric acid is used for etching a silver bracelet but not a gold bracelet.

SULPHURIC ACID

INTRODUCTION

1) Why was Sulphuric acid initially called 'oil of vitiriol'.

PREPARATION OF SULPHURIC ACID

2) Select the correct answer in each of the following pertaining manufacture of sulphuric acid by Contact process.
A) The catalyst used is - Platinum, iron, vanadium pentoxide.
B) The promoter used is -- sodium oxide, potassium oxide, lead.
C) The chemical formula of oleum obtained in the absorption of Tower is -- H₂SO₇ , H₂S₂O₇, HS₂O₇.
D) The product obtained in the contact tower is ---Sulphur Dioxide, sulphur trioxide, phosphoric acid, Sulphuric acid.
E) The substance added to pyrosulphoric acid to give sulphuric acid is -- Sulphur, Sulphur Dioxide, water, sulphurous acid.

PROPERTIES OF SULPHURIC ACID

19) Name the iron in dilute sulphuric acid responsible for turning methyl orange pink.

20) Name a metallic oxide which reacts with dilute sulphuric acid forming a soluble normal salt.

21) Using a metallic carbonate, a metallic sulphite and a metallic sulphide, how would you illustrate the typical properties of a dilute acid.

22) Give the two steps of dissociation of sulphuric acid.

23) State the basicity of Sulphuric acid. Name another acid having the same basicity.

24) State two physical properties shown by concentric sulphuric acid which differ from those shown by concentric nitric  and hydrochloric acid.

25) Complete the statement by surplying the correct words in the incorrect statement given -- The oxidizing property of sulphuric acid is due to the fact that yields nascent oxygen.

26) Concentrated sulphuric acid reacts with carbon liberating two gases, Sulphur dioxide and carbon dioxide. State which of the two is not the oxidised product.

27) Name
A) an acidic coloured gas.
B) an acidic colourless gas.
C) a concentrated Acid which reacts with hydrogen sulphide to give the same yellow non metallic product in each case.

28) A black mark forms on a piece of wood on with concentric sulphuric acid is added by a dropper.

29) Name the acid which reacts with concentric sulphuric acid to give two gases as the dehydrated product.

30) Give a reason why conc. Sulphuric acid changes the colour of hydrated copper sulphate on reaction with it but no colour change is seen when it is added to washing soda.

TESTS FOR SULPHURIC ACID

31) Name a metal which reacts with concentric sulphuric acid on heating to evolve Sulphur Dioxide.

32) Give a reason why dense white fumes are evolved when a glass rod dipped in ammonium is kept over a beaker containing sodium chloride and hot concentric Sulphuric acid.

33) What do you see when dil. Sulphuric acid is added to lead nitrate solution. Give a reason why the observation differs when the same acid is added to Copper nitrate solution.

USES OF SULPHURIC ACID

34) Name the following obtained from Sulphuric acid --
A) a nitrogenous fertilizer.
B) a Hydracid
C) an oxyacid.
D) an explosive.

35) What would you add to concentric sulphuric acid to obtain iodine. State the chemical property of conc. sulphuric acid involved in the reaction.

ORGANIC CHEMISTRY

INTRODUCTION
₂₆ ₂₄ ₂₂ ₂₄ ₂₂ ₂₄ ₂₂ ₂₆
1) State why Ethane[C₂H₆] is called a hydrocarbon but ethanol [C₂H₅OH ] is not. 

2) State which of the following reasons is responsible for formation of a large number of organic compounds --
A) show slow incomplete molecular reactions
B) have tendency by which the element in the compound forms chains of identical atoms
C) elements in the compound have ability to form strong covalent bonds.
D) can be classified into homologous series.
E) show isomerism.

3) State three important source of organic compounds.

HOMOLOGOUS SERIES -- ORGANIC COMPOUNDS

4) Give a reason why organic compounds are grouped into homologous series but inorganic are not.

5) if the general Formula of a particular homologous series is CₙH₂ₙ and CₙH₂ₙ₋₂ respectively, state the formulas of the first three hydrocarbons of each series.

STRUCTURE- ORGANIC COMPOUNDS

6) Differentiate between a molecular formula and structural formula of an organic compound.

7) If the molecular formula of a  hydrocarbon is C₃H₈ , C₂H₄ , C₃H₄,  respectively -- write it's condensed structural formula.

8) State the alkyl group and the functional group in each of the following--
A) methyl chloride 
B) methyl alcohol
C) acetaldehyde
D) vinegar 
E) Acetone 
G) chloroethane 

ISOMERISM

1) Give reasons why --
A) organic compounds exhibit isomerism
B) the number of isomers possible of a given molecular formula increases with increase in number of carbon atoms.
C) butane and pentane exhibit chain isomerism.

NOMENCLATURE- ORGANIC COMPOUNDS

10) Explain the term 'nomenclature' as applied to organic compounds.

11) Give the IUPAC name of the following Ethane italiances from the following--
A) ethane
B) ethylene
C) acetylene
D) butane
E) 1- butylene
F) propylene
G) methyl acetylene

HYDROCARBONS

12) State the general formula of alkynes from the following--
CₙH₂ₙ₊₂ , CₙH₂ₙ₋₂ , CₙH₂ₙ.

13) Draw the relevant structural formula of each of the following --
A) marsh gas
B) a paraffin other than methane containing two carbon atoms
C) an olefin containing a carbon-carbon double bond.
D) acetylene
E) ethyl Bromide.
F) ethanol.
G) acetaldehyde
H) acetic acid
I) Acetone

14) State which of the following are saturated organic compounds and which are unsaturated ---
C₂H₄ , C₂H₆ , C₂H₂ , CH₄ , C₃H₆ , C₃H₄ .

15) Give a reason why Saturday organic compounds are less reactive and undergo substitution reactions while unsaturated organic compounds are more reactive and undergo addition reactions.

16) State which of the following pertain to hydrocarbons--
A) aromatic organic compounds.
B) aliphatic closed chain organic compounds.
C) aliphatic open chain organic compounds.
D) compounds containing carbon and hydrogen.
E) compounds containing carbon and hydrogen only
F) divided into main groups saturated and unsaturated 
G) exhibits isomerism.

17) From the following list of compounds state the following :
A) Methane (Mars gas), Ethane, ethene, ethyne, Acetic Acid , methanol, ethyl chloride.
A) The organic compounds
B) the hydrocarbons
C) one hydrocarbon having a double covalent bond between the carbon atoms.
D) one hydrocarbons having a triple covalent bond between the carbon atoms.
E) one hydrocarbon which undergoes substitution reactions
F) two hydrocarbons which undergoes addition reactions.
G) the hydrocarbon whose molecular formula is C₂H₆ 
H) the hydrocarbon whose molecular formula is C₂H₄
I) the hydrocarbon whose molecular formula is C₂H₂
J) the hydrocarbon whose IUPAC name is ethene.

18) What is the special feature of the structure of C₂H₄ and C₂H₂.

19) What type of reaction is common to
A) both C₂H₄ and C₂H₂
B) C₂H₆ 

20) 'Ethane, ethene, ethyne and acetic acid are called hydrocarbons'. Give a reason why the statement is incorrect.

ALKANES, ALKENES AND ALKYNES

21) Give the laboratory preparation of Methane and ethane from Sodium acetate and sodium propionate respectively.

22) What are the substitution reactions. How would you obtain--
A) carbon tetrachloride from methane
B) hexagloroethane from ethane.

23) State the products of 
A) complete
B) incomplete Combustion of ethane.

24 Starting from methane how would you obtain formic acid.

25) Select the products of oxidation of Ethane using an oxidizing agent from the following products-- formaldehyde, ethanol , methanol, acetaldehyde, formic acid, Acetic Acid.

26) State the products of pyrolysis of methane at relevant temperatures.

27) name the acid for converting ethyl alcohol to ethylene. State the chemical property of the said acid responsible for the conversion.

28) Select the product of catalytic hydrogenation of Ethene-- Ethyne, ethane, methanol, ethanol.

29) How would you obtain 1,2 dibromoethane from ethane. State why the given reaction serves as a chemical test for ethene. Give a reason why the conversion of ethene to 1, 2 dichloroethane does not similarly serve as a test for ethene.

30) Give a reaction of Ethene with concentrated sulphuric acid.

31) State the process used for conversion of Ethene to polyethylene.

32) Give a reason why ethylene and acetylene are used for welding and cutting metals.

33) Name a compound added to cold water to acetylene in the laboratory.

34) State the reactant and the conditions required to convert ethyne to ethene Ethane respectively.

35) How does the reaction of Ethyne with Chlorine and bromine respectively differ from that of Ethene with the same reactants.

36) Give a reason why Ammoniacal  copper(II) chloride can be used to distinguish between ethene and ethyne while alkaline potassium permanganate is required to distinguish between ethane and ethene.

37) Give the preparation of methanol and ethanol by hydrolysis of alkyl halides. How would you obtain ethanol from ethene. Convert ethanol to --
A) ethene 
B) Acetic Acid 
C) ethyl acetate.

Monday, 20 February 2023

CHEMISTRY TEST PAPER (X)

              TEST PAPER - 1     
        (One hour and a half) 
_______________________________________Section I is Compulsory and attempt any four questions from Section II.
The intended marks for questions or parts of questions, are given in brackets [ ]
________________________________________
         SECTION I (40 Marks)
Compulsory: To be attended by all candidates.

Question 1
a) Answer the following questions relating your answer only to the gases in the list given below:
     Ammonia, hydrogen chloride, Sulphur Dioxide, Nitrogen, Oxygen, hydrogen, nitric oxide, methane, ethane.
 i) Two gases which react under relevant conditions to give a gas which turns a solution of potassium mercuric or iodide brown.
 ii) A gas which is absorb by iron[II] sulphate solution to give a brown addition compound.
iii) Two gases which react to give a reddish brown acidic gas.
iv) Two gases which react in presence of a catalyst at elevated temperatures to give an alcohol.
v) Two gases which react to give a solid which reacts with an alkali to give back one of the reactant gases.             [5

b) The following questions pertain to chemical bonding :
 i) Differentiate between the terms -- ' electrovalent bond' and 'covalent bond'.
ii) Draw the electron dot structure and orbit structure to depict the formation of
A) Sodium chloride.
B) Carbon tetrachloride.            
[²³₁₁Na,  ³⁵₁₇Cl, ¹²₆C]                              [6]

c) In this question you are required to supply the word/s that will make each sentence into a correct statement which is to be written down in full.
Example:  Magnesium nitride reacts with water to liberate ammonia.
Answer:  Magnesium nitride reacts with warm water to liberate ammonia.
 i) Activity series is a series arranged according to their decreasing reactivity.
ii) Ammonia reacts with lead[II] oxide liberating nitrogen.
iii) Aqua regia contains one part of a night ride nitric acid and three parts of nitric acid and three parts of hydrochloric acid.
iv) Ethyl alcohol is dehydrated by sulphuric acid at elevated temperatures liberating ethene gas.
v) Anions migrate during electrolysis and get discharged.                                  [5]

d) i) Give a reason why pure water is termed as a non-electrolyte while acidified what is an electrolyte.
ii) Name the product formed at the anode during electrolysis of aqueous sodium silver cyanide solution.
iii) State which of the following salt is weak electrolyte--
 Silver nitrate, Sodium carbonate, Copper chloride.
iv) State which of the following substance contains both ions and molecules ---
 Sodium hydroxide solution, Acetic Acid, molten lead bromide.
v) Write the equation for the reaction which takes place at the anode during electrolysis of acidified water.           [5]

e) i) What is the empirical formula of  compound having the following percentage composition :
Fe= 73.38% and O= 27.62% [Fe=56, O=16] 
ii) Iron pyrites [FeS₂] on roasting in air [oxygen] give iron[III] oxide and Sulphur dioxide. Calculate the weight of iron pyrites which must be roasted to produce 5000 g. of Sulphur dioxide gas. [S= 32].
iii) Combustion of ethane yields carbon dioxide and water vapour. Calculate the volume of carbon dioxide form that STP and the number of moles of oxygen needed for the combustion of 60 g of Ethane.                                          [8] 

f) What do you see when:
i) Bromine is passed into a solution of ethyne in an inert solvent.
ii) Ammonia-oxygen mixture is passed over the heated Platinum.
iii) Le[II] oxide is reacted the dilute nitric acid and the residual solution formed is mixed with sodium chloride solution.
iv) Zinc nitrate is heated strongly in air.
v) Hydrogen sulphide gas is bubbled through concentrated sulphuric acid and the gas liberated is then bubbled through iron[III] sulphate solution.
vi) Excess ammonium Hydroxide is added to the solution formed on reaction between lead carbonate and dilute nitric acid is excess.                                   [6]

g) Write balanced equations for each of the following reactions involving an oxide.
i) Lead[IV] oxide and concentrated hydrochloric acid.
ii) Lead [II] oxide(heated) and Ammonia.
iii) Zinc oxide and dilute nitric acid.
iv) Sodium oxide and Sulphur dioxide.
v) Iron [III] oxide and Aluminium.        [5]


         SECTION II (40 Marks)
        Attempt any 4 questions 

Question  2
a) Define the following periodic properties.
 i) Ionization potential.
ii) Electronegativity.                               [2]

b) State the following pertaining to the Periodic Table.
i) The period of the Periodic Table which has two elements in its period.
ii) The period to which the element carbon belongs.
iii) The elements in period 2 with the highest and potential.
iv) The noble gas present in period 2 of the Periodic Table.                              [4]

c) Supply the missing word/s in the blanks below.
 Sodium is an___metal belonging to group______of the Periodic Table. It has _____ electron/s in its valence shell and is a strong _____ agent.                       [4]

Question 3
a) Differentiate between the following terms:.                                                [3]
i) Basicity of acids and acidity of based.
ii) Concentrated acid and strong acid.
iii) Dibasic acid and diacidic base.

b)i) Define a metal and a non-metal on basis of Ionization.
ii) Compare a metal and a non-metal on basis of reaction with dilute acids.
iii) State a characteristic property of 'alkali metals' present in Group I A with a specific reason for the same.             [3]

c) i) Name an ore of sulphur used in the Contact Process which on roasting yields sulphur dioxide gas
ii) Name the gas evolved when zinc reacts with the final product of Contact Process.                                              [2]

d) State which chemical property of sulphuric acid is involved in the following conversion:
i) Nitre to aqua fortis.
ii) Hydrogen sulphide to sulphur.       [2]

Question 4

a) Give the IUPAC name and common name of the following hydrocarbons--
i) CH₄ 
ii) C₃H₆                                               [2]

b) i) Give a reason why the compound in a(i) above is called saturated organic compound.
ii) State the characteristic and typical reactions of the organic compound in  a(i) above.
iii) Draw the electronic structure of the organic compound C₂H₂.          [3]

c) i) Name the first chlorination product obtained when CH₄ and C₂H₆ react with chlorine respectively.
ii) What is the special feature of C₂H₄ and C₂H₂ which differentiates them from the hydrocarbons in a(i) above.
iii) What type of reactions undergone by the compounds C₂H₄ and C₂H₂.
iv) What is added to ethyl alcohol to obtain ethene in its laboratory preparation.                                       [5]

Question 5

a) What must be added to sodium chloride in the laboratory preparation of Hydrogen chloride gas.                     [1]

b) Write the equation for the reaction which takes place in (a) above.           [1]

c) Starting from hydrochloric acid how would you obtain --
i) Chlorine using lead [IV] oxide.
ii) Chlorine using bleaching powder.
iii)  Carbon dioxide using a soluble metallic carbonate.
iv) Hydrogen sulphide using a metallic sulphide.                                               [4]

d) Name the following:
i) A salt formed when hydrogen chloride reacts with heated iron.
ii) The oxidizing agent in Aqua regia.
iii) A metallic chloride insoluble in water and dilute nitric acid but soluble in liquor ammonia solution.
iv) The neutral gas obtained when hydrogen chloride undergoes thermal dissociation.                                         [4] 

Question 7

a)  Calcium nitrate decomposes on heating to give calcium oxide, nitrogen dioxide and oxygen.
i) Write the balanced equation for the thermal decomposition.
 Calculate:
ii) The volume of Nitrogen dioxide obtained at STP.
iii) The weight of the calcium oxide obtained when 4.1 g of calcium nitrate is heated. [Ca= 40, O= 16, N= 14]            [4]

b) Ammonia burns in oxygen of the air with a yellowish green flame, forming nitrogen and water as the only products.
i) Write the balanced equation for burning of ammonia in oxygen.
ii) Determine the volume of oxygen used and the volume of Nitrogen obtained when 400cc of ammonia burns in oxygen.                                                   [4]

c) Calculate the percentage of oxygen in nitre. (K=39, N= 14, O=16).                  [2]