Grade 10
Chapter: Chemical Reactions and Equations
PT1 Revision Worksheet
I.
MCQ
1. Magnesium ribbon is rubbed before burning because it has a coating of
(a) basic magnesium carbonate
(b) basic magnesium oxide
(c) basic magnesium sulphide
(d) basic magnesium chloride
2. Which of the following are exothermic processes?
(i) Reaction of water with quick lime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor (crystals)
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)
3. Give the ratio in which hydrogen and oxygen are present in water by volume.
(a) 1:2
(b) 1:1
(c) 2:1
(d) 1:8
4. A substance ‘X’ is used in white-washing and is obtained by heating limestone
in the absence of air. Identify ‘X’.
(a) CaOCl2
(b) Ca (OH)2
(c) CaO
(d) CaCO3
5. When Ag is exposed to air it gets a black coating of
(a) AgNO3
(b) Ag2S
(c) Ag2O
(d) Ag2CO3
6. Which of the following is an endothermic process?
(a) Dilution of sulphuric acid
(b) Sublimation of dry ice
(c) Condensation of water vapours
(d) Respiration in human beings
7. In the double displacement reaction between aqueous potassium iodide and
aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While
performing the activity if lead nitrate is not available, which of the following
can be used in place of lead nitrate?
(a) Lead sulphate (insoluble)
(&) Lead acetate
(c) Ammonium nitrate
(d) Potassium sulphate
8. What type of chemical reactions take place when electricity is passed through
water?
(a) Displacement
(b) Combination
(c) Decomposition
(d) Double displacement
9. When S02 gas is passed through saturated solution of H2S, which of the
following reaction occurs?
(a) SO2 + 2H2S → 2H20 + 3S
(b) SO2 + 2H2S → H20 + 3S
(c)SO2 + H2S → H2O + S
(d) SO2 + H2O → SO3 + H2
10. Pb + CuCl2 → PbCl2 + Cu
The above reaction is an example of:
(a) combination
(b) double displacement
(c) decomposition
(d) displacement
11. During electrolysis of water, if the volumes of oxygen and hydrogen evolved at
the electrodes are Vo and VH respectively, then Vo/VH is
(a) 4
(b) 2
(c) ½
(d) ¼
12. In order to balance the following chemical equation, the values of the
coefficients x and y respectively are:
x Pb(NO3)2
2 PbO + NO2 + O2
a) 2,4
b) 2,2
c) 2,3
d) 4,2
II.
Following questions consist of two statements – Assertion (A) and
Reason (R). Answer these questions selecting the appropriate option
given below:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
13. Assertion (A) : When HCl is added to zinc granules, a chemical reaction
occurs.
Reason (R) : Evolution of a gas and change in colour indicate that the chemical
reaction is taking place.
14. Assertion (A): Zinc reacts with sulphuric acid to form zinc sulphate and
hydrogen gas and it is a displacement reaction.
Reason (R): Zinc reacts with oxygen to form zinc oxide
15. Assertion (A): In a balanced chemical equation, total mass of the reactants is
equal to the total mass of the products.
Reason (R): Mass can neither be created nor destroyed during a chemical
change.
16. Assertion (A): Zinc reacts with sulphuric acid to form zinc sulphate and
hydrogen gas and it is a displacement reaction.
Reason (R): Zinc reacts with oxygen to form zinc oxide
III.
Answer the following
17. State the type of chemical reactions, represented by the following equations :
(Board Term I, 2014)
(a) A + BC → AC + B
(b) A + B → C
(c) PQ + RS → PS + RQ
(d) A2O3 + 2B → B2O3 + 2A
18. 1 g of copper powder was taken in a China dish and heated. What change takes
place on heating? When hydrogen gas is passed over this heated substance, a
visible change is seen in it. Give the chemical equations of reactions, the name
and the colour of the products formed in each case.
19. Mention with reason the colour changes observe when:
(i) silver chloride is exposed to sunlight.
(ii) copper powder is strongly heated in the presence of oxygen.
(iii) a piece of zinc is dropped in copper sulphate solution
20. Lead nitrate solution is added to a test tube containing potassium iodide
solution.
(a) Write the name and colour of the compound precipitated.
(b) Write the balanced chemical equation for the reaction involved.
(c) Name the type of this reaction justifying your answer
21. 2 g of silver chloride is taken in a China dish and the China dish is placed in
sunlight for some time. What will be your observation in this case? Write the
chemical reaction involved in the form of a balanced chemical equation.
Identify the type of chemical reaction
22. Identify the type of reactions taking place in each of the following cases and
write the balanced chemical equation for the reactions.
(a) Zinc reacts with silver nitrate to produce zinc nitrate and silver.
(b) Potassium iodide reacts with lead nitrate to produce potassium nitrate and
lead iodide
23. 2 g of ferrous sulphate crystals are heated in a dry boiling tube. (Al 2019,
Board Term 1, 2017, 2016)
(a) List any two observations.
(b) Name the type of chemical reaction taking place.
(c) Write balanced chemical equation for the reaction and name the products
formed.
24. Decomposition reactions require energy either in the form of heat or light or
electricity for breaking down the reactants. Write one equation each for
decomposition reactions where energy is supplied in the form of heat, light and
electricity
25. Take 3 g of barium hydroxide in a test tube, now add about 2 g of ammonium
chloride and mix the contents with the help of a glass rod. Now touch the test
tube from outside.
(i) What do you feel on touching the test tube?
(ii) State the inference about the type of reaction occurred.
(iii) Write the balanced chemical equation of the reaction involved
26. A solution of potassium chloride when mixed with silver nitrate solution, an
insoluble white substance is formed. Write the chemical reaction involved and
also mention the type of the chemical reaction.
27. Identify the substances that are oxidised and the substances that are reduced in
the following reactions. (Board Term I, 2015)
(a) Fe2O3 + 2Al → Al2O3 + 2Fe
(b) 2PbO + C → 2Pb + CO2
28. Mention the type of chemical reaction that takes place when: (Board Term I,
2013)
(i) a magnesium ribbon is burnt in air.
(ii) limestone is heated.
(iii) silver bromide is exposed to sunlight.
(iv) electricity is passed through acidified water.
(v) ammonia and hydrogen chloride are mixed with each other.
Write the chemical equation for each reaction.
29. A Name the type of chemical reaction represented by the following equation:
30. Write the balanced equation for the. following reaction and identify the type of
reaction in each case.
(i) Potassium bromide + Barium iodide—-> Potassium iodide + Barium
bromide.
(ii) Hydrogen(g) + Chlorine(g)—-> Hydrogen chloride(g)