The correct formula for the paramagnetic acid is:

Match the following:

Compound	Oxidation number
$1$. $CrO_5$	$a$. $+6$
$2$. $H_2SO_4$	$b$. $+1$
$3$. $C_4OCl_2$	$c$. $-1$
$4$. $(CH_3)_2SO$	$d$. $+2$

The oxidation number and the electronic configuration of sulphur in $H_2SO_4$ is

Assign the oxidation number to the underlined element in each of the following species:
$1$. $K_2\underline{Mn}O_4$
$2$. $Ca\underline{O}_2$
$3$. $Na\underline{B}H_4$
$4$. $KAl(\underline{S}O_4)_2 \cdot 12H_2O$

An acidified solution of sodium thiosulfate is unstable because in thiosulfate,the two sulfur atoms are in:

What is the oxidation number of carbon in $CH_2Cl_2$?