Question

${28NO}_3^{-}+{3As}_2{S}_3+{4H}_{2}O⟶{6AsO}_4^{3-}+28NO+{9SO}_4^{2-}+H^{+}$
What will be the equivalent mass of ${As}_2{S}_3$?

Answer 1

$28N{O}_3^{-}+3A{s}_2{S}_3+4H_{2}O⟶6As{O}_4^{3-}+28NO+9S{O}_4^{2-}+H^{+}$

Oxidation state of $As$ in $A{s}_2{S}_3=+3$

Oxidation state of $As{O}_4^{3-}=+5$

$\therefore$ Change in oxidation state of $As=2$

$\therefore$ Change in oxidation state of $A{s}_2{S}_3=4$

$\therefore$ Equivalent weight of $A{s}_2{S}_3=\frac{MolecularweightofA{s}_2{s}_3}{4}$

=$\frac{246}{4}$

=$61.5g$