Which of the following reactions does not involve either oxidation or reduction?
$I. \ 2Cs + 2H_2O \to 2CsOH + H_2$
$II. \ 2CuI_2 \to 2CuI + I_2$
$III. \ NH_4Br + KOH \to KBr + NH_3 + H_2O$
$IV. \ 4KCN + Fe(CN)_2 \to K_4[Fe(CN)_6]$

Balance the following redox reactions using the oxidation number and ion-electron method:
$(1) \ Zn + NO_3^- + H^+ \to Zn^{2+} + N_2O + H_2O$
$(2) \ I^- + O_2 + H_2O \to I_2 + OH^-$
$(3) \ MnO_4^- + C_2H_5OH \to Mn^{2+} + CH_3COOH$

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$MnS(s) + 2HCl(aq) \longrightarrow MnCl_2(aq) + H_2S(g)$

Oxidising power of chlorine in aqueous solution can be determined by the parameters indicated below:
$\frac{1}{2} Cl_{2(g)}$ $\xrightarrow{\frac{1}{2} \Delta_{diss} H^{\Theta}} Cl_{(g)}$ $\xrightarrow{\Delta_{eg} H^{\Theta}} Cl^{-}_{(g)}$ $\xrightarrow{\Delta_{Hyd} H^{\Theta}} Cl^{-}_{(aq)}$
(using the data,$\Delta_{diss} H_{Cl_2}^{\Theta} = 240 \ kJ \ mol^{-1}$,$\Delta_{eg} H_{Cl}^{\Theta} = -349 \ kJ \ mol^{-1}$,$\Delta_{Hyd} H_{Cl}^{\Theta} = -381 \ kJ \ mol^{-1}$) will be ............. $kJ \ mol^{-1}$.

$A$ few drops of $KMnO_4$ solution are added to an acidic solution containing an anion. Which of the following,if present,will $NOT$ cause a change in the color of the $KMnO_4$ solution?

Metal sulphate $(A) \xrightarrow{\text{Heat}}$ Oxide $(B) +$ Gas $(C) +$ Gas $(D) \xrightarrow{Cr_2O_7^{2-} / H^{+}}$ Green solution $\xrightarrow[\text{Excess}]{Na_2O_2}$ Yellow solution $(E)$. Compound $A, B, C, D$ and $E$ are respectively: