Question

A white salt of lead on heating decomposes to give brown fumes and a yellow residue in left behin

(a) Name the salt

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Answer 1

The chemical name of white salt is Lead nitrate Pb(NO3)2.

On heating, the salt produces brown fumes. It implies that it contains nitrate ion. The salt can be possibly any nitrate but if the yellow residue left after heating implies the salt to be lead nitrate.

The equation involved can be shown as:

2Pb (NO3)2 → 2PbO + 4NO2 + O2

Colourless Yellow Brown fumes

Answer 2

a) Pb(NO3)2

yellow residue-PbO

brown fume- NO2