Question

The volume of $M/20HCl$ required to neutralise $20ml$ of $M/10NaOH$ is:

• A. $60ml$
• B. $10ml$
• C. $40ml$
• D. $20ml$

Answer 1

The correct option is C $40ml$

We know that $V_1\times S_1=V_2\times S_2$ $V⟶$ Volume, $S⟶$ Strength

Given $V_1=20ml$ $S_1=M/10$, $S_2=M/20$

So, $20\times \frac{M}{10}=\frac{M}{20}\times V_2$

$\Rightarrow V_2=40ml$

Hence, volume required is $40ml$ .