SCIENCE & TECHNOLOGY (Class-10)
Chapter 1. Chemical Reaction and Equations

SET - 3

1. When iron is heated with sulphur iron sulphide is formed. What is the reaction called? (1 mark)

2. What type of reaction is represented by the digestion of food in our body? (1 mark)

3. What is that reaction called in which one element takes the place of another element in a compound? (1 mark)

4. What happens to copper sulphate solution when a piece of iron metal is placed in it? (1 mark)

5. A reaction takes place with the evolution of heat energy. What is this reaction called? (1 mark)

6. Write the balanced equation for the following chemical reactions. (2 marks)
(i) Hydrogen + Chlorine ------> Hydrogen chloride
(ii) Barium chloride + Aluminium sulphate ------> Barium sulphate + Aluminium chloride
(iii)Sodium + Water -------> Sodium hydroxide + Hydrogen.

7.Write a balanced chemical equations with sate symbols for the following reactions: (2 marks)
(i)Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride.
(ii)Sodium hydrogen solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water.

8. A solution for a substance ‘X’ is used for white – washing. (2 marks)
(i)Name the substance ‘X’ and write its formula.
(ii)Write the reaction of the substance ‘X’ named in (i) above with water.

9. What way the two reactions in each of the following pairs are different from each other?
(i) (a) NH3 (g) + H2O (l) -----> NH4OH (aq) (3 marks)
(b) 2 Mg (s) + O2 (g) --------> 2 MgO (s)

(ii) (a) Zn (s) + CuSO4 (aq) -----------> ZnSO4 (aq) + Cu (s)
(b) H2S (aq) + CuSO4 (aq) ------------> CuS (s) + H2 SO4 (aq)

(iii) (a) CaCO3 ----------> CaO (s) + CO2 (g)
(b) 2H2O (l) ---------> 2H2 (g) + O2 (g)

10. What is meant by a displacement reaction? Give two examples. (3 marks)

11. What are the advantages of using a chemical equation for the representation of a chemical reaction?