Question

A student has 7.05 g of zinc powder, 1.60 L of a 3.40 M calcium nitrate solution, and 1.50 L of a 1.60 M lead(II) nitrate solution. Which of these two solutions will react with the zinc powder?
1) calcium nitrate
2) lead(II) nitrate

Answer 1

Answer: Zinc will react with lead (II) nitrate solution.

Explanation:

Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element from its chemical reaction.

The reactivity of metal is determined by a series known as reactivity series. The metals lying above in the series are more reactive than the metals which lie below in the series.

General equation for single displacement reaction follows:

$A+BC\rightarrow AC+B$

When zinc is reacted with calcium nitrate, the reaction does not take place as zinc is less reactive than calcium. Zinc lies below in the series than calcium.

$Zn+Ca(NO_3)_2\rightarrow \text{No reaction}$

But, when zinc is reacted with lead (II) nitrate, the reaction do take place as zinc is more reactive than lead. Zinc lies above in the series than lead.

The chemical equation for the reaction of zinc and lead (II) nitrate follows:

$Zn+Pb(NO_3)_2\rightarrow Zn(NO_3)_2+Pb$

Hence, zinc will react with lead (II) nitrate solution.