Question

A metal nitrate 'A' on heating gives a metal oxide along with evolution of a brown coloured gas 'B' and a colourless gas, which helps in burning. Aqueous solution of 'A' when reacted with potassium iodide forms a yellow precipitate.

(a) Identify 'A' and 'B'

(b) Name the types of both the reactions involved in the above statement.

Answer 1

The metal nitrate (A) is lead nitrate (Pb(NO₃​)₂​) on heating it produces lead oxide, Nitrogen dioxide (B) and oxygen gas

(a) 2Pb(NO₃​)₂ ​→ 2PbO + 4NO₂ ​+ O₂​

on reaction with potassium iodide mixture of lead iodide and potassium nitrate forms.

Therefore A = [Pb(NO₃​)₂​), B = NO₂

(b) Pb(NO₃​)₂​ + 2KI → PbO₂​ + 2kNO₃​

• Decompostion type Reaction.
• Double displacement type Reaction.