Question

7. A light metal 'Z reacts with sodium hydroxide to release a gas.
i. Identify the metal Z and the gas released. (½+½)
ii. Write a confirmatory test for this gas

Answer 1

Answer:

i-it is hydrogen

Explanation:

Answer 2

(i) The metal Z is aluminium and the gas released is hydrogen gas.

(ii) The confirmatory test for hydrogen gas is that the gas gives a popping sound when a lighted splint is placed in the test tube containing the gas.

Explanation:

• A light metal is aluminium.
• When aluminium reacts with sodium hydroxide, it gives sodium tetrahydroxoaluminate and hydrogen gas is released.

• The reaction is given as: $\[2Al + 2NaOH + 6{H_2}O \to 2Na[Al{(OH)_4}] + 3{H_2}\]$

• Hydrogen gas can be confirmed by placing a lighted splint is placed in the test tube containing the gas. It gives a popping sound.