The cell reaction of micro electrochemical cell formed during rusting of iron is:-

1.  ${\mathrm{O}}_2\left(\mathrm{g}\right)<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>4{\mathrm{H}}^{\oplus }\left(\mathrm{aq}\right)<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>4{\mathrm{e}}^{-}<mspace\; width="1em"></mspace>\to <mspace\; width="1em"></mspace>2{\mathrm{H}}_2\mathrm{O}<mspace\; width="1em"></mspace>\left(\mathrm{l}\right)$

2. $4{\mathrm{Fe}}^{+2}\left(\mathrm{aq}\right)<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{O}}_2\left(\mathrm{g}\right)<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)<mspace\; width="1em"></mspace>\to <mspace\; width="1em"></mspace>4\mathrm{FeO}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>4{\mathrm{H}}^{\oplus }\left(\mathrm{aq}\right)$

3. $2\mathrm{Fe}\left(\mathrm{s}\right)<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{O}}_2\left(\mathrm{g}\right)<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>4\mathrm{H}{°}^{\oplus }\left(\mathrm{aq}\right)<mspace\; width="1em"></mspace>\to 2{\mathrm{Fe}}^{+2}\left(\mathrm{aq}\right)<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{aq}\right)$

4.  $\mathrm{Fe}\left(\mathrm{s}\right)<mspace\; width="1em"></mspace>\to {\mathrm{Fe}}^{+2}\left(\mathrm{aq}\right)<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>2{\mathrm{e}}^{-}$

Which of the following is an incorrect statement :- 

1. Mercury cell is a primary cell providing a constant potential

2. During recharging lead storage cell works as electrolytic cell

3. Galvanised iron does not rust

4. In electrolytic cell reduction occurs at anode and in galvanic cell oxidation takes place at anode

For the cell reaction

${\mathrm{Cu}}_{{\mathrm{c}}_1}^{+2}<mspace\; width="1em"></mspace>\left(\mathrm{aq}\right)<mspace\; width="1em"></mspace>+\hspace{0.17em}\mathrm{Zn}\left(\mathrm{s}\right)<mspace\; width="1em"></mspace>\stackrel{<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>}{\to }<mspace\; width="1em"></mspace>{\mathrm{Zn}}_{{\mathrm{C}}_2}^{+2}<mspace\; width="1em"></mspace>\left(\mathrm{aq}\right)<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>\mathrm{Cu}\left(\mathrm{s}\right)$

the change in free energy at a given temperature is a function of 

(1) lnC₁

(2) ln$\frac{{\mathrm{C}}_2}{{\mathrm{C}}_1}$ 

(3) ln (C₁ +C₂)

(4) lnC₂

EMF of the following cell will be zero if

Pt(H₂)|H⁺||H⁺|(H₂)Pt

    P1   C1  C₂    P₂

(1) C₁P₁ = C₂P₂

(2) C₁P₂ = P₂C₁

(3) ${\mathrm{C}}_1^2{\mathrm{P}}_2<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>{\mathrm{C}}_2^2{\mathrm{P}}_1$

(4) None of the above.

${\mathrm{E}}_{\raisebox{1ex}{${\mathrm{Ni}}^{+2}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{Ni}$}\right.}^0<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>-0.25<mspace\; width="1em"></mspace>\mathrm{V},<mspace\; width="1em"></mspace>{\mathrm{E}}_{\raisebox{1ex}{${\mathrm{Au}}^{+3}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{Au}$}\right.}^0<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>1.50<mspace\; width="1em"></mspace>\mathrm{V}$

the emf of Voltaic cell

$\mathrm{Ni}<mspace\; width="1em"></mspace>|<mspace\; width="1em"></mspace>{\mathrm{Ni}}^{+2}(1\mathrm{M})<mspace\; width="1em"></mspace>||<mspace\; width="1em"></mspace>{\mathrm{Au}}^{+3}(1\mathrm{M})<mspace\; width="1em"></mspace>\mathrm{Au}<mspace\; width="1em"></mspace>\mathrm{is}:-$

(1) 1.25 V

(2) -1.75 V

(3) 1.75 V

(4) 4 V

The same amount of electric current is apassed through aqueous solution of MgSO₄ and AlCl₃. If 2.8 g Mg metal is deposited at amount of Al metal deposited in second cell will be

1. 2.1 g

2. 2.49 g

3. 3.15 g

4. 3.73g

The potential of the following concentration cell at room temperature is-

$\mathrm{Pt},<mspace\; width="1em"></mspace>{\mathrm{H}}_2\left(\mathrm{g}\right)<mspace\; width="1em"></mspace>\left|{\mathrm{H}}^{\oplus }\right({10}^{-6}\mathrm{M}\left)\right|\left|{\mathrm{H}}^{\oplus }\right({10}^{-4}<mspace\; width="1em"></mspace>\mathrm{M})<mspace\; width="1em"></mspace>|<mspace\; width="1em"></mspace>{\mathrm{H}}_2\left(\mathrm{g}\right),<mspace\; width="1em"></mspace>\mathrm{Pt}$

(1) -0.118V

(2) -0.0591V

(3) 0.118V

(4) 0.0591V

Select the incorrect statement for dry cell

(1) Mn is reduced from Mn⁺⁴ to Mn⁺³

(2) NH₃ gas libreted out

(3) Zn is used as anode

(4) Paste of NH₄Cl and ZnCl₂ is used

What is the current efficiency of an electrode deposition of Cu metal from CuSO₄ solution in which 9.8 gm copper is deposited by the passage of 5 amperes current for 2 hours?

1. 41.4 %

2. 50%

3. 75%

4. 82.8 %

During electrolysis, 2A current is passed through an electrolytic solution for 965 s. The number of moles of electrons passed will be

1. 0.02

2. 0.01

3. 200

4. 0.037