A brown gas is released on heating lead nitrate. Which gas is it?
Answer and explanation
Correct answer: Nitrogen dioxide
On strong heating, lead nitrate undergoes thermal decomposition: 2Pb(NO3)2 → 2PbO + 4NO2 + O2. Nitrogen dioxide, NO2, is a reddish-brown gas, so option B is correct. Oxygen is also produced in the reaction but is colourless, which is why it does not account for the brown fumes. Hydrogen and sulphur dioxide are not products of lead nitrate decomposition.
Frequently asked questions
What is the correct answer to this question?
Nitrogen dioxide
Why is this the correct answer?
On strong heating, lead nitrate undergoes thermal decomposition: 2Pb(NO3)2 → 2PbO + 4NO2 + O2. Nitrogen dioxide, NO2, is a reddish-brown gas, so option B is correct. Oxygen is also produced in the reaction but is colourless, which is why it does not account for the brown fumes. Hydrogen and sulphur dioxide are not products of lead nitrate decomposition.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
