This document contains 13 multiple choice and short answer questions about chemical reactions: 1) It asks for the balanced chemical equation for the reaction of magnesium and hydrochloric acid. 2) It asks if a combination reaction can also be a redox reaction. 3) It covers a variety of chemical reactions including the reaction of sodium with water, copper sulfate changing color due to an iron nail, and several other examples.

1. Test of Chemical reaction
1) Write a chemical equation when magnesium metal reacts with aqueous hydrochloric acid to
produce a solution of magnesium chloride and hydrogen gas? (1)
2) Can a combination reaction be redox reaction? (1)
3) What happens when sodium reacts with water?
4) Why does the color of copper sulphate solution change, when an iron nail is dipped in it? )
5) What type of chemical reactions take place when: (a)Limestone is
heating?
(b)A magnesium wire is burnt in air?
(c)Electricity is passed through water?
(d)Ammonia and hydrogen chloride are mixed?
(e)Silver bromide is exposed to sunlight?
6) Write a balanced chemical equation with state symbols for the following reactions:-
i. Solution of barium chloride and sodium sulphate in water react to give
insoluble barium sulphate and the solution of sodium chloride.
ii. Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in
water) to produce sodium chloride solution and water.
7) When a white compound ‘X’ is placed under sunlight, it turns grey, Give the name of
chemical reaction and write the balanced chemical equation. ?
8) Oxidation reaction have some harmful effects. Comment on the sentence?
9) What are the various ways to make a chemical reaction more informative?
10) On adding a drop of barium chloride solution to an aqueous solution of sodium
sulphite,
white precipitate is formed.
(a) Write a balanced chemical equation of the reaction involved?
(b) What other name can be given to this precipitation reaction?
11) A silver article generally turns black when kept in the open for few days. The article when
rubbed with toothpaste again starts shining.
(a) Why do silver article turns black when kept in open for few days? Name the
phenomenon involved?
(b) Name the black substance formed and give its chemical formula?
12) Write chemical equation of the reaction in which the following changes have taken place
with an example of each:
(a) Change in colour
(b) Change in temperature
(c) Formation of precipitate
13)the equations given below, state giving reasons, whether substances have been oxidized
or reduced.

2. (i) PbO + CO –> Pb + CO2
(ii) H2S + Cl2–>2HCl + S.
Balance the equations
1. HNO +Ca(OH)2 → Ca(NO3)2 + H2O
2. NaCl + AgNO3 → AgCl + NaNO3
3. BaCl2 +H2SO4 → BaSO4 +HCl