1
JEE Main 2023 (Online) 13th April Evening Shift
Numerical
+4
-1

At $$298 \mathrm{~K}$$, the standard reduction potential for $$\mathrm{Cu}^{2+} / \mathrm{Cu}$$ electrode is $$0.34 \mathrm{~V}$$.

Given : $$\mathrm{K}_{\mathrm{sp}} \mathrm{Cu}(\mathrm{OH})_{2}=1 \times 10^{-20}$$

Take $$\frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.059 \mathrm{~V}$$

The reduction potential at $$\mathrm{pH}=14$$ for the above couple is $$(-) x \times 10^{-2} \mathrm{~V}$$. The value of $$x$$ is ___________

2
JEE Main 2023 (Online) 13th April Morning Shift
Numerical
+4
-1

A metal surface of $$100 \mathrm{~cm}^{2}$$ area has to be coated with nickel layer of thickness $$0.001 \mathrm{~mm}$$. A current of $$2 \mathrm{~A}$$ was passed through a solution of $$\mathrm{Ni}\left(\mathrm{NO}_{3}\right)_{2}$$ for '$$\mathrm{x}$$' seconds to coat the desired layer. The value of $$\mathrm{x}$$ is __________. (Nearest integer) ( $$\rho_{\mathrm{Ni}}$$ (density of Nickel) is $$10 \mathrm{~g} \mathrm{~mL}$$, Molar mass of Nickel is $$60 \mathrm{~g} \mathrm{~mol}^{-1}$$ $$\left.\mathrm{F}=96500 ~\mathrm{C} ~\mathrm{mol}^{-1}\right)$$

3
JEE Main 2023 (Online) 11th April Evening Shift
Numerical
+4
-1

The number of correct statements from the following is __________

A. $$\mathrm{E_{\text {cell }}}$$ is an intensive parameter

B. A negative $$\mathrm{E}^{\ominus}$$ means that the redox couple is a stronger reducing agent than the $$\mathrm{H}^{+} / \mathrm{H}_{2}$$ couple.

C. The amount of electricity required for oxidation or reduction depends on the stoichiometry of the electrode reaction.

D. The amount of chemical reaction which occurs at any electrode during electrolysis by a current is proportional to the quantity of electricity passed through the electrolyte.

4
JEE Main 2023 (Online) 11th April Morning Shift
Numerical
+4
-1

In an electrochemical reaction of lead, at standard temperature, if $$\mathrm{E}^{0}\left(\mathrm{~Pb}^{2+} / \mathrm{Pb}\right)=\mathrm{m}$$ Volt and $$\mathrm{E}^{0}\left(\mathrm{~Pb}^{4+} / \mathrm{Pb}\right)=\mathrm{n}$$ Volt, then the value of $$\mathrm{E}^{0}\left(\mathrm{~Pb}^{2+} / \mathrm{Pb}^{4+}\right)$$ is given by $$\mathrm{m-x n}$$. The value of $$\mathrm{x}$$ is ___________. (Nearest integer)