In acidic medium,$H_2O_2$ changes $Cr_2O_7^{2-}$ to $CrO_5$ which has two $(-O-O-)$ bonds. Oxidation state of $Cr$ in $CrO_5$ is

Match the following compounds with the oxidation number of the central atom (or specific atom in question):

Compound	Oxidation number
$1$. $C_6H_{12}O_6$ (Carbon)	$a$. $+1$
$2$. $CCl_4$ (Carbon)	$b$. $0$
$3$. $NH_4Cl$ (Nitrogen)	$c$. $+4$
$4$. $Ba(H_2PO_2)_2$ (Phosphorus)	$d$. $-3$

Assign oxidation number to the underlined elements in each of the following species:
$(a)$ $NaH_2\underline{P}O_4$
$(b)$ $NaH\underline{S}O_4$
$(c)$ $H_4\underline{P_2}O_7$
$(d)$ $K_2\underline{Mn}O_4$
$(e)$ $Ca\underline{O_2}$
$(f)$ $Na\underline{B}H_4$
$(g)$ $H_2\underline{S_2}O_7$
$(h)$ $KAl(\underline{S}O_4)_2 \cdot 12H_2O$

What is the oxidation number of sulphur in $Na_2S_4O_6$?

The oxidation state of sulphur in $H_2S_2O_7$ is

What is the oxidation state of carbon in $CaC_2$ and $K_2C_2O_4$ respectively?