JEE Main - 9th April 2016

$20 \mathrm{mL}$ of $0.02{\mathrm{MK}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ solution is used for the titration of $10 \mathrm{mL}$ of ${\mathrm{Fe}}^{2+}$ solution in the acidic medium. The molarity of ${\mathrm{Fe}}^{2+}$ solution is____$\times {10}^{-2}\mathrm{M}$

In the titration of ${\mathrm{KMnO}}_4$ and oxalic acid in acidic medium, the change in oxidation number of carbon at the end point is

The Plot of $\mathrm{pH}$-metric titration of weak base ${\mathrm{NH}}_4\mathrm{OH}$ vs strong acid $\mathrm{HCl}$ looks like

Match List-I with List-II, match the gas evolved during each reaction.

Choose the correct answer from the options given below

For kinetic study of the reaction of iodide ion with ${\mathrm{H}}_2{\mathrm{O}}_2$ at room temperature :

(A) Always use freshly prepared starch solution.

(B) Always keep the concentration of sodium thiosulphate solution less than that of $\mathrm{KI}$ solution.

(C) Record the time immediately after the appearance of blue colour.

(D) Record the time immediately before the appearance of blue colour.

(E) Always keep the concentration of sodium thiosulphate solution more than that of $\mathrm{KI}$ solution.

Choose the correct answer from the options given below

A compound '$\mathrm{X}$' is a weak acid and it exhibits colour change at $\mathrm{pH}$ close to the equivalence point during neutralization of $\mathrm{NaOH}$ with ${\mathrm{CH}}_3\mathrm{COOH}$. Compound '$\mathrm{X}$' exists in ionized form in basic medium. The compound '$\mathrm{X}$' is

In which of the following reactions the hydrogen peroxide acts as a reducing agent?

The number of electrons involved in the reduction of permanganate to manganese dioxide in acidic medium is _____ .