One mole of sulphur monochloride  $\left({\mathrm{S}}_2{\mathrm{Cl}}_2\right)$ loses six moles of electrons to form a compound of sulphur. Oxidation state of sulphur in the product is (Assume chlorine atoms doesn’t show any change in oxidation state and both sulphur atoms appear in the product)

${\stackrel{+1}{\mathrm{S}}}_2{\mathrm{Cl}}_2$

Total oxidation number of sulphur/mole of  ${\mathrm{S}}_2{\mathrm{Cl}}_2$ = +2
1 mole of ${\mathrm{S}}_2{\mathrm{Cl}}_2$  loses ‘6’ moles of electrons
$\therefore$ Total increase in oxidation number = 6
Sum of oxidation numbers of two sulphur atoms in one mole of product = 2+6 = +8
$\therefore$2x = +8
         x = +4
Oxidation number of sulphur in the product = +4