The equivalent weight of the metal, when $1.0 \mathrm{g}$ of metal nitrate gave $0.86 \mathrm{g}$ of metal sulphate is:

 

A mixture of ${\mathrm{Cu}}_2\mathrm{S}$ and $\mathrm{CuS}$ on oxidation by $\mathrm{Al}{\left({\mathrm{MnO}}_4\right)}_3$ in acidic medium gives ${\mathrm{Cu}}^{2+}$ and ${\mathrm{SO}}_2$. If molar masses of ${\mathrm{Cu}}_2\mathrm{S}, \mathrm{CuS}$ and $\mathrm{Al}{\left({\mathrm{MnO}}_4\right)}_3$ are ${\mathrm{M}}_1, {\mathrm{M}}_2$ and ${\mathrm{M}}_3$, respectively, then for this reaction which one are correct?