Question

Which of the following reactions will not occur? Why not?
(a) ${\mathrm{MgSO}}_4\left(\mathrm{aq}\right)+\mathrm{Cu}\left(\mathrm{s}\right)\underset{}{\to }{\mathrm{CuSO}}_4\left(\mathrm{aq}\right)+\mathrm{Mg}\left(\mathrm{s}\right)$
(b) ${\mathrm{CuSO}}_4\left(\mathrm{aq}\right)+\mathrm{Fe}\left(\mathrm{s}\right)\underset{}{\to }{\mathrm{FeSO}}_4\left(\mathrm{aq}\right)+\mathrm{Cu}\left(\mathrm{s}\right)$
(c) ${\mathrm{MgSO}}_4\left(\mathrm{aq}\right)+\mathrm{Fe}\left(\mathrm{s}\right)\underset{}{\to }{\mathrm{FeSO}}_4\left(\mathrm{aq}\right)+\mathrm{Mg}\left(\mathrm{s}\right)$

Answer 1

Reactions (a) and (c) will not occur because copper is less reactive than magnesium. So, it cannot displace magnesium from its salt solution, the equation of which is shown in reaction (a).
Similarly, iron is less reactive than magnesium. So, it cannot displace magnesium from its salt solution, the equation of which is shown in reaction (c).