Page No 10:
Question 2:
Why is the amount of gas collected in one of the test tubes in Activity 1.7 double of the amount collected in the other? Name this gas.
Page No 13:
Question 1:
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Page No 14:
Question 1:
Which of the statements about the reaction below are incorrect?
(a) Lead is getting reduced.
(b) Carbon dioxide is getting oxidised.
(c) Carbon is getting oxidised.
(d) Lead oxide is getting reduced.
(i) (a) and (b)
(ii) (a) and (c)
(iii) (a), (b) and (c)
(iv) all
Page No 15:
Question 3:
What happens when dilute hydrochloric acid is added to iron filings? Tick the correct answer.
(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.
Page No 15:
Question 4:
What is a balanced chemical equation? Why should chemical equations be balanced?
Page No 15:
Question 9:
What does one mean by exothermic and endothermic reactions? Give examples.
Page No 15:
Question 11:
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
Page No 16:
Question 13:
What is the difference between displacement and double displacement reactions? Write equations for these reactions.
Page No 16:
Question 15:
What do you mean by a precipitation reaction? Explain by giving examples.
