When $10 \, mL$ of an aqueous solution of $KMnO_{4}$ was titrated in acidic medium,an equal volume of $0.1 \, M$ aqueous solution of ferrous sulphate was required for complete discharge of colour. The strength of $KMnO_{4}$ in grams per litre is $...... \times 10^{-2}$. (Nearest integer)
[Atomic mass of $K=39, Mn=55, O=16$]

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

$AgCl$ on fusion with $Na_2CO_3$ forms

Ferrous and ferric ions in solution may be distinguished by using

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 ............. $kJ \ mol^{-1}$.

Which of the following reactions are redox reactions?
$I. \, Cr_2O_7^{2-} + 2OH^- \to 2CrO_4^{2-} + H_2O$
$II. \, Zn + CuSO_4 \to ZnSO_4 + Cu$
$III. \, 2MnO_4^- + 3Mn^{2+} + 4OH^- \to 5MnO_2 + 2H_2O$
$IV. \, 2Cu^+ \to Cu + Cu^{2+}$