The total change in the oxidation state of manganese involved in the reaction of $KMnO_4$ and potassium iodide in the acidic medium is $..........$.

In the given reaction,calculate the number of electrons lost by iron:
$3Fe + 4H_2O \to Fe_3O_4 + 4H_2$

In a balanced equation $H_2SO_4 + x \ HI \to H_2S + y \ I_2 + z \ H_2O$,the values of $x, y, z$ are

Equivalent mass of the oxidizing agent in the reaction $SO_2 + 2H_2S \to 3S + 2H_2O$ is

Identify the correct statements about the following stoichiometric equation.
$aP_4 + bOH^{-} + cH_2O \longrightarrow dPH_3 + eH_2PO_2^{-}$
$I$. $a+b+c=5$
$II$. $b+c-e=3$
$III$. The oxidation state of $P$ in $H_2PO_2^{-}$ is $+1$.

In the equation $H_2S + 2HNO_3 \to 2H_2O + 2NO_2 + S$,the equivalent weight of hydrogen sulphide is: