Question

Write the colour of evolving gases resiue in the test tubeand chemical equation on heating of lead nitrate

Answer 1

The colour of the gas evolved from the dry test tube is reddish brown fumes with pungent smell.

The colour of the residue left behind on heating the lead nitrate in a dry test tube is orange reddish colour.

Balanced Chemical Equation:

2Pb(NO3)2(s)----∆--->2PbO(s)+4NO2(g)+O2(g)

Here,

• 2 atoms of lead is present in the reactant side and in the product side equally.
• 12 atoms of oxygen is present in the reactant side and in the product side equally.
• 4 atoms of nitrogen is present in the reactant side and in the product side equally.

Answer 2

chemical eqn. -

2Pb(NO3)2----Δ--->2PbO+4NO2 +O2

In the reaction, the NO2 gas is evolved which is brown in colour.

And the residue left behind i.e.the leadmonoxide (PbO) is yellow in colour(when its hot) and becomes white (when its cold).

Hope this helps!❤✌