In the following schematic diagram for the preparation of hydrogen gas as shown as figure, what would happen if following changes are made? (a) In place of zinc granules, same amount of zinc dust is taken in the test tube. (b) Instead of dilute sulphuric acid, dilute hydrochloric acid is taken. (c) Sodium hydroxide is taken in place of dilute sulphuric acid and the tube is heated. (ii) How do metal carbonates and metal hydrogen carbonates react will acids?

(i) (a) Hydrogen gas will evolve with greater speed.

(b) Almost same amount of gas is evolved.

(c) If sodium hydroxide is taken, hydrogen gas will be evolved.

𝑍𝑛     +    2𝑁𝑎𝑂𝐻    →     𝑁𝑎₂𝑍𝑛𝑂₂     +     𝐻₂

.                                    𝑆𝑜𝑑𝑖𝑢𝑚 𝑧𝑖𝑛𝑐𝑎𝑡𝑒

(ii) All metal carbonates and hydrogen carbonates react with acids to form a corresponding salt, carbon dioxide and water.

Metal carbonate + Acid → Salt + Carbon dioxide + Water

Metal hydrogencarbonate + Acid → Salt + Carbon dioxide + Water

For example, sodium carbonate reacts with dilute hydrochloric acid as follows:

𝑁𝑎₂𝐶𝑂₃(𝑠) + 2𝐻𝐶𝑙(𝑎𝑞) → 2𝑁𝑎𝐶𝑙(𝑎𝑞) + 𝐻₂𝑂(𝑙) + 𝐶𝑂₂(𝑔)

Sodium hydrogen carbonate reacts with dilute hydrochloric acid as follows:

𝑁𝑎𝐻𝐶𝑂₃(𝑠) + 𝐻𝐶𝑙(𝑎𝑞) → 𝑁𝑎𝐶𝑙(𝑎𝑞) + 𝐻₂𝑂(𝑙) + 𝐶𝑂₂(𝑔)