Question

The salt of an oxyacid of a metal $M$ contains one sulphur and four oxygen atoms. The oxyacid of the salt is:

• A. $H_{2}S{O}_4$
• B. $H_{2}S{O}_3$
• C. $H_2{S}_2{O}_7$
• D. $H_{2}S$

Answer 1

Answer: (A)

$H_{2}S{O}_4$

Let the formula of the salt of an oxyacid of a metal $M$ containing one sulphur and four oxygen atom be $MS{O}_4$. It is a neutral molecule therefore total charge should be zero.

Let the valency of metal ion be $x$, valency of $S$ is $+6$ and of $O$ is $-2$
Therefore, $x+6+4\times (-2)=0$ or $x=+2$

It is a bivalent metal ion and therefore can be replace by two monovalent ion of $H^{+}$ to form the corresponding oxyacid with balanced valency ($M^{2+}\to 2H^{+}$). Thus $MS{O}_4$ can form from oxyacis of $H_{2}S{O}_4$.

Option $A$ is correct.