What can you say about the P^{​​​​​​H} of a solution that liberate CO_{​​​​​2} from sodium carbonate? Write the balanced chemical equation for the reaction.

Q. What can you say about the pH of a solution that liberates carbon dioxide from sodium carbonate?

Q.

(a) A solution has a $p^H$ of 7. Explain how you would :

(i) increase ist $p^H$; (ii) decrease its $p^H$;

(b) If a solution changes the colour of litmus from red to blue, what can you say about its $p^H$?

(c) What can you say about the $p^H$ of a solution, that liberates carbon dioxide from sodium carbonate ?

Q.

(a) What happens when dilute hydrochloric acid is added to sodium carbonate ? Write a balanced chemical equation of the reaction involved.

(b) Which gas is liberated when dilute hydrochloric acid reacts with sodium carbonate ? How will you test for the presence of this gas ?

Q. Write a balanced chemical equation for the following :

Q. On adding dilute hydrochloric acid to copper oxide powder, the solution formed is blue-green.
(a) Predict the new compound formed which imparts a blue-green colour to solution.
(b) Write a balanced chemical equation of the reaction which takes place.
(c) On the basis of the above reaction, what can you say about the nature of copper oxide?