The standard emf of galvanic cell involving 3 moles of electrons in its redox reaction is 0.59 V. The equilibrium constant for the reaction of the cell is

• 10²⁵

• 10²⁰

• 10¹⁵

• 10³⁰

E₁, E₂ and E₃ are the emfs of the following three galvanic cells respectively.

(i) Zn (s) | Zn²⁺ (0.1 M) || Cu²⁺ (1M) | Cu (s)

(ii) Zn (s) | Zn²⁺ (1 M) || Cu²⁺ (1M) | Cu (s)

(iii) Zn (s) | Zn²⁺ (1 M) || Cu²⁺ (0.1M) | Cu (s)

Which one of the following is true?

• E₂ > E₁ > E₃

• E₁ > E₂ > E₃

• E₃ > E₁ > E₂

• E₃ > E₂ > E₁

The standard emf of a galvanic cell involving 2 moles of electrons in its redox reaction is 0.59 V. The equilibrium constant for the redox reaction of the cell is

• 10²⁰

• 10⁵

• 10

• 10¹⁰

9.65 C of electric current is passed through fused alyhdrous MgCl₂. The magnesium metal thus obtained is completely converted into a Grignard reagent. The number of moles of Grignard reagent obtained is

• 5 × 10^-4

• 1 × 10^-4

• 5 × 10^-5

• 1 × 10^-5

E₁, E₂, E₃ are the emf values of the three galvanic cells respectively.

$$\begin{gathered} \left(\mathrm{i}\right)\hspace{0.17em}\mathrm{Zn}| {\mathrm{Zn}}_{1\mathrm{M}}^{2+}|| {\mathrm{Cu}}_{0.1\mathrm{M}}^{2+}|\mathrm{Cu} \\ \left(\mathrm{ii}\right)\hspace{0.17em}\mathrm{Zn}| {\mathrm{Zn}}_{1\mathrm{M}}^{2+}|| {\mathrm{Cu}}_{1\mathrm{M}}^{2+}|\mathrm{Cu} \\ \left(\mathrm{iii}\right)\mathrm{Zn}| {\mathrm{Zn}}_{0.1\mathrm{M}}^{2+}|| {\mathrm{Cu}}_{1\mathrm{M}}^{2+}|\mathrm{Cu} \end{gathered}$$

Which one of the following is true?

• E₁> E₂ >E₃

•  E₂ >E₃ >E₁

• E₃ >E₂ > E₁

• E₁> E₃ >E₂

Which one of the following has a potential more than zero?

• Pt, $\frac{1}{2}$H₂ (1 atm) | HCl (2M)

• Pt, $\frac{1}{2}$H₂ (1 atm) | HCl (0.1 M)

• Pt, $\frac{1}{2}$H₂ (1 atm) | HCl (0.5 M)

• Pt, $\frac{1}{2}$ H₂ (1 atm) | HCl (1M)

100 mL of 0.1 M acetic acid is completely neutralized using a standard solution of NaOH. The volume of ethane obtained at STP after the complete electrolysis of the resulting solution is

• 56 mL

• 224 mL

• 560 mL

• 112 mL

The emf of a galvanic cell constituted with the electrode Zn²⁺|Zn (-0.76V) and Fe²⁺|Fe (-0.41V) is

• -0.35V

• + 1.17V

• +0.35V

• -1.17V

For hydrogen-oxygen fuel cell at 1 atm and 298 K

H₂ (g) + $\frac{1}{2}$O₂ (g) → H₂O (l) ; $∆$G° = -240 kJ

E° for the cell is approximately, (Given F = 96500 C)

• 2.48 V

• 1.25 V

• 2.5 V

• 1.26 V

While charging the lead storage battery,

• PbSO₄ on anode is reduced to Pb

• PbSO₄ on cathode is reduced to Pb

• PbSO₄ on cathode is oxidised to Pb

• PbSO₄ on anode is oxidised to PbO₂