The value of $x$ in the partial redox equation $MnO_4^- + 8H^{+} + xe^- \rightleftharpoons Mn^{2+} + 4H_2O$ is

When $SO_2$ gas is passed through an acidic solution of $K_2Cr_2O_7$,what happens?

Assign $A, B, C, D$ from the given type of reaction for the following chemical equation:
$N_2 + 3H_2 \longrightarrow 2NH_3$

How many moles of electrons are needed to convert one mole of nitrate ion to hydrazine?

$NaClO$ solution reacts with $H_2SO_3$ as,$NaClO + H_2SO_3 \to NaCl + H_2SO_4$. $A$ solution of $NaClO$ used in the above reaction contained $15 \ g$ of $NaClO$ per litre. The normality of the solution would be

Balance the following redox reactions using the oxidation number and ion-electron method:
$(1) H_2S + Fe^{3+} \to Fe^{2+} + S + H^{+}$
$(2) Cu + NO_3^{-} \to Cu^{2+} + NO_2$
$(3) Sn + NO_3^{-} + H^{+} \to Sn^{2+} + NH_4^{+} + H_2O$
$(4) As + NO_3^{-} + H^{+} \to AsO_4^{3-} + NO_2 + H_2O$