Question

$3{Cl}_2+6NaOH⟶5NaCl+\underset{–}{NaCl{O}_3}+3H_{2}O$
The equivalent weight of the underlined compound by taking its molecular weight as $M$ is :

• A. $E=\frac{3M}{4}$
• B. $E=\frac{3M}{5}$
• C. $E=\frac{2M}{5}$
• D. none of these

Answer 1

Answer: (B)

$E=\frac{3M}{5}$

$3{Cl}_2+6NaOH⟶5NaCl+\underset{–}{NaCl{O}_3}+3H_{2}O$
The equivalent weight of the underlined compound by taking its molecular weight as $M$ is $E=\frac{3M}{5}$.
The oxidation number of chorine changes from +5 to 0. The total change in the oxidation number is +5. This change is effective for 3 chlorine molecules. Hence, for 1 chlorine molecule, the change in the oxidation number is 5/3. Equivalent weight is the ratio of the molecular weight to change in the oxidation number.