The standard Potentials at 25⁰ C for the half reactions are given against them below:

${\mathrm{Zn}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{Zn};{\mathrm{E}}^0=-0.762\mathrm{V}$

 ${\mathrm{Mg}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{Mg};{\mathrm{E}}^0=-2.37\mathrm{V}$

When Zn dust is added to a solution of MgCl₂

• A

  Magnesium is precipitated

• B

  Zinc dissolves in the solution

• C

  Zinc chloride is formed

• D

  No reaction takes place