Question

$$S{O}_{2}C{l}_2$$(sulphuryl chloride) reacts with water to give a mixture of
$$H_{2}S{O}_4$$ and $$HCl$$. What volume of $$0.2MBa{\left(OH\right)}_2$$ is needed to
completely neutralize $$25mL$$ of $$0.2MS{O}_{2}C{l}_2$$ solution.
(A) $$25mL$$
(B) $$50mL$$
(C) $$100mL$$
(D) $$200mL$$

Answer 1

Hint: As we know that $$H_{2}S{O}_4$$ and $$HCl$$ both are strong acids, whereas $$Ba{\left(OH\right)}_2$$ is a strong base so this is a strong acid strong base titration. If we know the number of moles of $$H_{2}S{O}_4$$ and $$HCl$$ then we will easily find out the number of moles of $$Ba{\left(OH\right)}_2$$ and hence we can easily calculate the volume of $$0.2MBa{\left(OH\right)}_2$$.

Complete step by step answer:
The reaction of sulfuryl chloride reacts with water occurs as
$$S{O}_{2}C{l}_2+2H_{2}O\to H_{2}S{O}_4+2HCl$$
Now we will calculate the number of moles of $$25mL$$ of $$0.2MS{O}_{2}C{l}_2$$ by the
formula
$$concentration(C)={\displaystyle \frac{numberofmoles(n)}{volume(V)}}----(i)$$
Rearranging the above formula, we get as
$$n=V\times C$$
Putting the values $$C=0.2M,V=25mL$$

$$\begin{gathered} \Rightarrow n=25mL\times 0.2M \\ \Rightarrow n=5mmol=5\times {10}^{-3}mole \end{gathered}$$
$\Rightarrow S{O}_{2}C{l}_2+2H_{2}O\to H_{2}S{O}_4+2HCl$

$5\times {10}^{-3}moles$	0	0
0	$5\times {10}^{-3}moles$	$10\times {10}^{-3}moles$

Therefore, the number of moles of $$Ba{\left(OH\right)}_2$$to neutralize $$H_{2}S{O}_4$$$$=5\times {10}^{-3}$$
And the number of moles of $$Ba{\left(OH\right)}_2$$ to neutralize $$HCl$$$$=5\times {10}^{-3}$$
So, the total number of moles of $$Ba{\left(OH\right)}_2$$ to neutralize both acids
$$=10\times {10}^{-3}$$
From the equation$$(i)$$we can easily find the volume of $$Ba{\left(OH\right)}_2$$ as
$$\begin{gathered} \Rightarrow V={\displaystyle \frac{n}{C}} \\ \Rightarrow V={\displaystyle \frac{10\times {10}^{-3}mole}{0.2M}} \\ \Rightarrow V=50\times {10}^{-3}L \\ \therefore V=50mL \end{gathered}$$

Note: The volume of $$Ba{\left(OH\right)}_2$$ is $$50mL$$. In acid base titration, the
number of moles of hydroxyl ions must be equal to the number of moles of hydrogen ions for
the complete neutralization.