JEE Main 2016 — Redox Reactions Question with Solution

According to law of equivalence,

Equivalence of acid = Equivalence of base.

Equivalence of acid = Normality x volume = 0.1 $$\times$$ v

As we know base produce OH^$$-$$ ion, so moles of base is same as moles of OH^$$-$$ ion = 0.04

Another formula of equivalence = n factor $$\times$$ number of moles

$$\therefore$$ Equivalance of base = n factor of OH^$$-$$ $$\times$$ moles of OH^$$-$$ = 1 $$\times$$ 0.04

As for any ion, the charge of that ion is the n factor of that ion. Here OH^$$-$$ has 1 negative charge so it's n factor = 1

$$\therefore$$ 0.1 $$\times$$ v = 1 $$\times$$ 0.04

$$\Rightarrow$$ v = 0.4 L

=   0.4 $$\times$$ 1000

=    400 ml.