Question

A student carries out the decomposition reaction of lead nitrate to form three simpler substances. One of the substances formed during this reaction is a brown coloured gas whereas another substance formed is a yellow coloured solid.
(a) What is the colour of lead nitrate?
(b) How is the decomposition reaction of lead nitrate carried out?
(c) Name the brown coloured gas produced in this reaction.
​(d) Name the yellow solid formed in this reaction.

Answer 1

(a) Lead nitrate is of white colour.

(b) When lead nitrate is heated, it is decomposed into three simpler products - yellow coloured lead oxide, brown fumes of nitrogen dioxide and oxygen.

$\underset{\mathrm{white}}{\mathrm{Pb}({\mathrm{NO}}_3{)}_2}\left(\mathrm{s}\right)\stackrel{\mathrm{heat}}{\to }\underset{\mathrm{yellow}}{\mathrm{PbO}\left(\mathrm{s}\right)}+\underset{\mathrm{brown}\mathrm{fumes}}{{\mathrm{NO}}_2\left(\mathrm{g}\right)}+{\mathrm{O}}_2\left(\mathrm{g}\right)$

(c) Brown coloured gas is nitrogen dioxide.

(d) Yellow coloured solid formed is lead oxide.