The standard reduction potentials at 298 K for the following half-cell reactions are given on next page

                    $$\begin{gathered} {\mathrm{Zn}}^2\left(\mathrm{aq}\right)\hspace{0.17em}+ 2{\mathrm{e}}^{-} \rightleftharpoons \mathrm{Zn}\left(\mathrm{s}\right)\hspace{0.17em}-0.762 \\ {\mathrm{Cr}}^{3+}\left(\mathrm{aq}\right)\hspace{0.17em}+ 3{\mathrm{e}}^{-} \rightleftharpoons \mathrm{Cr}\left(\mathrm{s}\right)\hspace{0.17em}-0.74 \\ 2{\mathrm{H}}^{+}\left(\mathrm{aq}\right)\hspace{0.17em}+ 2{\mathrm{e}}^{-} \rightleftharpoons {\mathrm{H}}_2\left(\mathrm{g}\right)\hspace{0.17em}+0.00 \\ {\mathrm{Fe}}^{3+}\left(\mathrm{aq}\right)\hspace{0.17em}+ {\mathrm{e}}^{-} \rightleftharpoons {\mathrm{Fe}}^{2+}\left(\mathrm{aq}\right) +0.77 \end{gathered}$$

Which one of the following is the strongest reducing agent?

• Zn(s)

• Cr(s)

• H₂(s)

• Fe²⁺(aq)

412.

1 C electricity deposits

• 10.8 g of Ag

• 96500 g of Ag

• electrochemical equivalent of Ag

• half of electrochemical equivalent of Ag

Given, for Sn⁴⁺/ Sn²⁺, standard reductiona potential is 0.15 V and for Au³⁺/ Au, standard reduction potential is 1.5 V.

For the reaction,

3Sn²⁺ + 2Au³⁺ → 3Sn⁴⁺ + 2Au

the value of E${}_{\mathrm{cell}}^{°}$ is

• +1.35

• +2.55

• -1.35

• -2.55

The isotope tha causes skin disease is

• I¹³¹

• S³⁵

• P³¹

• None of these

According to Faraday's first law

• $\mathrm{w} = \frac{ 96500 \times \mathrm{E}}{\mathrm{I} \times \mathrm{t}}$

• $\mathrm{w} = \frac{ \mathrm{I} \times \mathrm{t} \times \mathrm{E}}{96500}$

• $\mathrm{E}=\frac{\mathrm{I} \times \mathrm{t} \times 96500}{\mathrm{w}}$

• $\mathrm{E} = \frac{ \mathrm{I} \times \mathrm{w}}{\mathrm{t} \times 96500}$

The standard reduction potential for Fe²⁺/Fe and Sn²+/Sn electrodes are - 0.44 and- 0.14 V respectively. For the cell reaction,  ${\mathrm{Fe}}^{+} + \mathrm{Sn} \to \mathrm{Fe} + {\mathrm{Sn}}^{2+}$  the standard emf is

• + 0.30 V

• - 0.58 V

• + 0.58 V

• - 0.30 V

How is electrical conductance of a conductor related with length and area of cross section of the conductor?

• G = κ· l· a^-1

• G = l· a· κ^-1

• G = κ· a· l^-1

• G = κ· a· l^-2

The overall reaction taking place at anode during electrolysis of fused sodium chloride using suitable electrode is

• oxidation of chloride

• reduction of sodium ions

• reduction of chlorine

• oxidation of sodium atoms

Which among the following solutions is not used in determination of the cell constant?

• 10^-2 M KCl

• 10^-1 M KCl

• 1 M KCl

• Saturated KCl

How many Faradays of electricity are required to deposit 10g of calcium from molten calcium chloride using inert electrodes? ( Molar mass of calcium = 40g mol^-1)

• 0.5 F

• 1F

• 0.25 F

• 2 F