Question

gas that is generated by excessive heating of lead nitrate crystals

Answer 1

When solid lead nitrate is heated strongly it turns yellow due to formation of lead oxide and a reddish brown gas is evolved which is nitrogen dioxide .

When the evolved gas is passed over wooden glowing splinters it rekindles.

This shows the presence of oxygen. When lead nitrate crystals are heated, lead (II) oxide, oxygen and nitrogen dioxide are formed.

Because of this property, lead nitrate is sometimes used in the making of fireworks.

Answer 2

Solution :-

On excessive heating, Lead Nitrate crystals decompose crackling sound and a brown gas, Nitrogen Dioxide (NO₂) is generated which has a very irritated smell. This gas turns blue litmus red. So, this gas is acidic in nature and also oxygen is liberated. A yellow solid residue of Lead Oxide (PbO) remains in the test tube.

Here is the equation -

2Pb(NO₃)2 ⇒ 2PbO(Lead Oxide) + 4NO₂(Nitrogen Dioxide) + O₂(Oxygen)