Question

A student while heating solid lead nitrate taken in a test tube would observe (1) white residue of PbO2
(2) green residue of NO2
(3) yellow residue of PbO
(4) brown residue of NO

Answer 1

Answer:

3 Option is correct

yellow residue of PbO

Explanation:

When a solid nitrate is heated in a test tube then,

A yellow residue Pbo is formed along with the evolution of reddish brown fumes of NO2 and a gas that lights a splinter (oxygen)

$PbNO_{3}$→$PbO+O_{2} +NO_{2}$

where as Pbo is a yellow residue

                NO2 is reddish brown fumes

Answer 2

Lead nitrate - Yellow Residue of PbO

Explanation:

Answer is option (c)

• When it is heated, it decomposes and breaks to yield lead oxide, oxygen & nitrogen di-oxide .  

• Lead Oxide - Yellow Coloured Substance

• Nitrogen di-oxide - Brown Coloured (Gas)

The chemical equation involved in the reaction is :

$2Pb(NO_3)_2 (s)$ -----> $2PbO (s) + 4NO_2 (s) + O_2 (g)$

Hence, Colour so obtained after heating the Lead nitrate is Yellow.