Question

X is a reddish brown element. When heated with dilute nitric acid it gives out a colourless gas y which turns into a reddish brown gas on coming into contact with air.

Answer 1

Answer:Reddish brown element X is Copper.

When heated with dilute nitric acid it produces a colourless gas Y is nitrogen dioxide NO2.

Explanation:

Answer 2

Answer:

X= Copper (Cu)

Y= Nitric oxide (NO)

Explanation:

Cu reacts with dil. HNO3 to give Copper nitrate, water and Nitric acid (colorless gas).

3Cu+ 8HNO3 ⟶ 3Cu(NO3)2 + 4H2O + 2NO

Nitric acid is unstable therefore it reacts with oxygen in the atmosphere to form NO2 (Reddish brown gas).

2NO + O2 ⟶ 2NO2