CHEMISTRY TERMINOLOGY - CHEMICAL REACTIONS
THE LANGUAGE OF CHEMISTRY
1) A symbol represents a short form of an element.
a) In most cases the first letter of an element was taken as the symbol for that element. Give two examples of the same.
b) In certain cases in the first letter along with the its small letter from its name were used as the symbols. Give two examples of the same.
c) In some cases the symbols were derived from their Latin names. Name two metals . Whose symbols are derived from the same.
d) Sulphur is represented by the symbol 'S'. State how the symbol represents the elements i) qualitatively [i.e., representation in terms of an atom] ii) quantitatively, [i.e., representation in terms of weight].
2) Give reasons for the following:
a) In hydrogen chloride the valency of the element chlorine is considered as one.
b) Certain metals exhibit more than one valency and showing 'variable valency '.
c) All equations must be balanced.
d) A chemical equation provides useful information about a reaction.
e) All chemical equations have their limitations.
3) State the valency and name the ion or radical in each of the following cases given below (The first example is completed for you):
Electrical ent positive ions or radicals
Symbol/Valency Name
a) K¹⁺ Potassium
b) Na
c) H
d) NH₄
e) Ca
f) Mg
g) Zn
h) Ba
i) Ni
i) Co
j) Al
k) Cr
Variable valencies
a) Cu¹⁺
b) Cu
c) Hg¹⁺
d) Hg
e) Fe²⁺
f) Fe
g) Mn²⁺
h) Mn
i) Pb²⁺
j) Pb
k) Pt²⁺
l) Pt
Electrovalent negative ion or radicals
Symbol/valency Name
a) Cl¹⁻ Chloride
b) ClO₃
c) ClO
d) Br
e) I
f) OH
g) NO₂
h) NO₃
i) HCO₃
j) HSO₃
k) HSO₄
l) AlO₂
m) MnO₄
n) SO₃
o) SO₄
p) S
q) CO₃
r) O
s) CrO₄
t) Cr₂O₇
u) ZnO₂
v) PbO₂
w) PO₄
x) N
y) C
4) State the valency of each of the elements in the respective compounds:
a) Sulphur in (i) sulphur dioxide
ii) sulphur trioxide
b) Nitrogen in i) Nitrogen monoxide
ii) Nitrogen dioxide
iii) dinitrogen oxide
iv) dinitrogen pentoxide
c) Copper in i) cupric oxide
ii) Cuprous oxide
5) Give the formulas of the following compounds whose metallic radical exhibits variable valency.
a) Cupric nitrate.
b) Cuprous chloride.
c) Iron(II) sulphate.
d) Mercuric nitrate.
e) Plumbous chloride.
f) Stannous chloride.
g) Mangannic sulphate.
h) Platinic chloride.
i) Mercurous chloride.
j) Iron [II] nitrate.
6) Give the name of the compounds whose formulas are listed below:
a) HNO₂ ___
b) HCO₃ |
c) H₂C₂O₄. |
d) H₃PO₄ | --- Acids
e) CH₃COOH _ |
g) Al(OH)₃
h) CaSiO₃.
i) Na₂ZnO₂.
j) K₂CrO₄.
k) Mg₃N₂.
7) A chemical equation is a shorthand form for a chemical change
a) 2KClO₃ ---∆--> 2KCl + 3O₂.
i) In the above reaction name the reactant and the products.
ii) State what the arrow in between indicates.
8) Balance the following equations.
a) CuO+ NH₃ --> Cu + H₂O + N₂.
b) NH₃ + Cl₂ --> HCl + NCl₃.
c) Mg₃N₂ + H₂O --> Mg(OH)₂ + NH₃.
d) Pb₃O₄ + HCl --> PbCl₂ + H₂O + Cl₂.
e) Manganese [IV] + Hydrochloric acid --> Manganese (II) Chloride+ Water + Chlorine.
f) Potassium hydroxide + Chlorine --> Potassium chloride + Potassium hypochlorite + Water.
g) Ammonium dichromate --> Chromiumoxide + Water+ Nitrogen.
h) Potassium sulphite + Nitric acid --> Potassium nitrate+ Water+ Sulphur dioxide.
i) Iron [II] chloride + Water + Sulphur dioxide --> Iron [II] Chloride+ Sulphuric acid+ Hydrochloric acid.
j) Copper+ Sulphuric acid --> Copper sulphate + Water+ Sulphur dioxide.
k) Iron [III] oxide + Carbon monoxide --> Iron + Carbon dioxide.
l) Sodium sulphite+ Sulphuric acid --> Sodium sulphate+ Water+ Sulphur dioxide.
m) Zinc + Sodium hydroxide --> Sodium zincate --> Hydrogen.
n) Aluminium+ Carbon dioxide --> Aluminium oxide + Carbon.
o) Sodium bicarbonate+ Aluminium sulphate --> Sodium sulphate+ Aluminium hydroxide+ Carbon dioxide.
p) Calcium hydroxide+ Ammonium sulphate --> Calcium sulphate+ Water+ Ammonia.
q) Nitric acid+ Magnesium carbonate --> Magnesium nitrate+ Water+ Carbon dioxide.
r) Iron [III] oxide+ Sulphuric acid --> Iron [III] sulphate+ Water.
s) Zinc sulphide+ Oxygen --> Zinc oxide+ Sulphur dioxide.
t) Carbon+ Nitric acid --> Carbon dioxide+ Water+ Nitrogen dioxide.
7) Match the different types of chemical reactions in column II with the meaning of the type of reactions in column I.
COLUMN I
a) A chemical reaction in which two or more elements or compounds react to form one new compound as a product.
b) A chemical reaction in which a chemical compound decomposes or splits up into two or more simpler substances. It is generally brought about by heat.
c) A chemical reaction which takes place when an element [or radical] has replaced another element in a compound.
d) A chemical reaction in which two reactants are both the decomposed to form new substances by exchanging their radicals.
e) A chemical reaction which employes a catalyst to alter the rate of a reaction.
f) A chemical reaction in which the products formed react together to form the original reactants depending on the conditions of the reaction.
g) A reaction in which a substance dissociates into two or more simpler substances on application of heat and is a reversible reaction.
h) A reaction which involves addition of oxygen or electronegative element or removal of hydrogen or electropositive element.
i) A reaction which involves addition of hydrogen or electropositive elements or removal of oxygen or electronegative element.
j) A chemical reaction which proceeds with evolution of heat energy.
k) A chemical reaction which proceeds with absorption of heat energy.
l) 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.
8) With reference to the reaction -- A to L in column II of the previous question no. 7 state the type of reaction/s to which each of the following belongs :
a) Addition of zinc to copper sulphate solution.
b) Heat on lead nitrate crystals.
c) Preparation of oxygen from potassium chlorate.
d) Conversion of ferrous chloride to ferric chloride using chlorine.
e) Formation of ammonia from nitrogen and hydrogen.
f) Liberation of hydrogen at the cathode acidified water.
g) Manufacture of glucose by green plants.
h) Formation of nitric oxide from Nitrogen and oxygen.
i) Addition of zinc to dilute sulphuric acid.
j) NH₄Cl <=> NH₃ + HCl.
k) 2KNO₃ --∆--> 2KNO₂ + O₂.
l) 2H₂O₂ --H₃PO₄--> 2H₂O + O₂.
m) PbBr₂ --> Pb²⁺ + 2Br¹⁻ [ions].
n) 2HgO --∆--> 2Hg + O₂.
o) N₂O₄ <=∆=> 2NO₂.
p) AgNO₃ + KCl --> AgCl + KNO₃.
q) Fe + S --> FeS.
r) H₂ + Cl₂ --> 2HCl.
ˢᵘⁿˡᶦᵍʰᵗ
s) C + H₂O --> CO.
t) Cl₂ + 2KI --> 2KCl + I₂.
u) 3Fe + 4H₂O <==∆=> Fe₃O₄ + 4H₂.
v) 2Cu + O₂ --> 2CuO.
w) Fe₂O₃ + 2Al --> Al₂O₃ + 2Fe.
x) KNO₃ + H₂SO₄ --> HNO₃ + KHSO₄.
y) 2FeCl₂ + Cl₂ --> 2FeCl₃.
z) Fe+ H₂SO₄ --> FeSO₄ + H₂.
a) SO₂ + Cl₂ --> SO₂Cl₂.
b) 3Ca + N₂ --> Ca₃N₂.
c) CuSO₄ + Fe --> FeSO₄ + Cu.
d) 4HNO₃ --> 2H₂O + 4NO₂ + O₂.
8) Oxidation and reduction reactions are generally termed as redox reactions . In the examples given below underline the oxidised product or reduced product in the respective reactions. Underline substance is the oxidising or reducing agent respectively.
Oxidation reactions
a) Cu + O₂ --> 2CuO.
b) H₂S + Cl₂ --> S + 2HCl.
c) 2FeCl₂ Cl₂ --> 2FeCl₃.
d) SO₂ + H₂O + Cl₂ --> H₂SO₄ + 2HCl.
e) H₂S + 2FeCl₃ ---> 2FeCl₂ + 2HCl + S.
f) Zn + H₂SO₄ --> ZnSO₄ + H₂.
g) Fe + S --> FeS.
h) 2Mg + SO₂ --> MgO + S.
i) 2H₂S + SO₂ --> 3S + 2H₂O.
j) S + 2H₂SO₄ ---> 3SO₂ + 2H₂O.
Reduction reactions
a) CuO + H₂ --> Cu + H₂O.
b) Br₂ + H₂S --> 2HBr + S.
c) 2FeCl₃ + H₂S --> 2FeCl₂ + 2HCl + S.
d) 2HgCl₂ + SnCl₂ --> Hg₂Cl₂ + SnCl₄.
e) 2FeCl₃ + SO₂ + 3H₂O --> 2FeCl₂ + 2HCl + H₂SO₄.
f) Fe₂(SO₄)₃ + 2H₂O + SO₂ --> 2FeSO₄ + 2H₂SO₄.
g) Cl₂ + 2H₂O + SO₂ --> 2HCl + H₂SO₄.
h) 2HNO₃ + SO₂ --> 2NO₂ + H₂SO₄.
i) 2KMnO₄ + 2H₂O + 5SO₂ --> 2MnSO₄ + K₂SO₄ + 2H₂SO₄.
j) K₂Cr₂O₇ + H₂SO₄ + 3SO₂ --> Cr₂(SO₄)₃+ K₂SO₄ + H₂O.
9) Name the following:
a) A coloured gaseous oxidising agent.
b) A liquid oxidising agent which on thermal decomposition in presence of a catalyst liberates oxygen.
c) A gaseous reducing agent containing Oxygen.
d) An acidic other than nitric and Sulphuric Acid which is an oxidizing agent.
e) A gaseous reducing agent neutral in nature other than carbon monoxide.
f) An oxidizing agent which liberates chlorine on heating with concentric hydrochloric acid.
g) Two neutral gases which react to give a basic gas and the reaction is exothermic.
h) Two neutral gases which react to give a neutral oxide and the reaction is exothermic.
i) A substance which decomposes by absorption of sound energy.
j) Two substances which react explosively on close physical contact.
No comments:
Post a Comment