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Q.
On strongly heating $Pb(NO_3)_2$ crystals, the gas formed is
The p-Block Elements - Part2
Solution:
When solid lead nitrate is heated strongly a it turns yellow due to formation of lead oxide and a reddish brown gas is evolved which is nitrogen dioxide.
$2Pb(NO_3)_2(s) \rightarrow 2PbO(s) + 4NO_2(g) + O_2(g)$