Question

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

• A. $MOH$
• B. $M(OH{)}_2$
• C. $M(OH{)}_3$
• D. $M_{2}OH$

Answer 1

Answer: (B)

$M(OH{)}_2$

Let the formula of the salt of an oxyacid of a metal M containing one sulphur and four oxygen atom be $MS{O}_4$
its a neutral molecule therefore total valency 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 $x=+2$
its a bivalent metal ion. Base of this metal will have formula as $M_a(OH{)}_b$
Also, its a neutral molecule therefore total valency should be zero. valency of $H$ is $+1$ and of $O$ is $-2$
therefore, $2a+b(1-2)=0$
or $b=2a$, thus formula is $M_1(OH{)}_2$ or $M(OH{)}_2$
option B is correct.