Question

Given the balanced ionic equation:

Answer 1

Answer : The correct option is, (4) 6.0 mol

Explanation :

The given balanced chemical equation is,

$3Pb^{2+}+2Cr\rightarrow 3Pb+2Cr^{3+}$

In this reaction, lead undergoes reduction and chromium undergoes oxidation.

Oxidation reaction : It is the reaction in which a substance looses its electrons. In this oxidation state increases.

Reduction reaction : It is the reaction in which a substance gains electrons. In this oxidation state decreases.

Half reactions of oxidation-reduction are :

Oxidation : $2Cr\rightarrow 2Cr^{3+}+6e^-$

Reduction : $3Pb^{2+}+6e^-\rightarrow 3Pb$

From the reduction reaction, we conclude that 6 moles of electrons gained by the 3 moles of lead ions.

Hence, the correct option is, (4) 6.0 mole