The hydrogen electrode is dipped in a solution of pH = 3 at 25°C. The potential of the cell would be [use value of $\frac{2.303 \mathrm{RT}}{\mathrm{F}}$ = 0.59 V]

• 0.059 V

• 0.088 V

• 0.178 V

• -0.177 V

The equivalent conductivity of a solution containing 2.54 g of CuSO₄, per L is 91.0 W^-1 cm²eq^-1. Its conductivity would be

• $2.9 \times {10}^{-3}{\mathrm{\Omega }}^{-1}{\mathrm{cm}}^{-1}$

• $1.8 \times {10}^{-2} {\mathrm{\Omega }}^{-1} {\mathrm{cm}}^{-1}$

• $2.4 \times {10}^{-4} {\mathrm{\Omega }}^{-1}{\mathrm{cm}}^{-1}$

• $3.6 \times {10}^{-3}{\mathrm{\Omega }}^{-1}{\mathrm{cm}}^{-1}$

$$\begin{gathered} {\mathrm{MnO}}_4^{-} + 8{\mathrm{H}}^{-} + 5{\mathrm{e}}^{-} \to {\mathrm{Mn}}^{2+} + 4{\mathrm{H}}_2\mathrm{O}; \mathrm{E}° = 1.51\mathrm{V} \\ {\mathrm{MnO}}_2 + 4{\mathrm{H}}^{+} + 2{\mathrm{e}}^{-} \to {\mathrm{Mn}}^{2+} + 2{\mathrm{H}}_2\mathrm{O}; \mathrm{E}° = 1.23 \mathrm{V} \mathrm{E}{°}_{{\mathrm{MnO}}_4^{-}|{\mathrm{MnO}}_2} \mathrm{is} \end{gathered}$$

• 1.70 V

• 0.91 V

• 1.37 V

• 0.548 V

Which of the following expressions correctly represents the equivalent conductance at infinite dilution of Al2(SO₄)₃ ? Given that ${\mathrm{\Lambda }}_{{\mathrm{Al}}^{3+}}^{°}$ and ${\mathrm{\Lambda }}_{{\mathrm{SO}}_4^{2-}}^{°}$ are the equivalent conductances at infinite dilution of the respective ions?

• $2{\mathrm{\Lambda }}_{{\mathrm{Al}}^{3+}}^{°} + 3{\mathrm{\Lambda }}_{{\mathrm{SO}}_4^{2-}}^{°}$

• ${\mathrm{\Lambda }}_{{\mathrm{Al}}^{3+}}^{°} + {\mathrm{\Lambda }}_{{\mathrm{SO}}_4^{2-}}^{°}$

• $({\mathrm{\Lambda }}_{{\mathrm{Al}}^{3+}}^{°}+ 3{\mathrm{\Lambda }}_{{\mathrm{SO}}_4^{2-}}^{°} )\times 6$

• $\frac{1}{3}{\mathrm{\Lambda }}_{{\mathrm{Al}}^{3+}}^{°}+ \frac{1}{2}{\mathrm{\Lambda }}_{{\mathrm{SO}}_4^{2-}}^{°}$

The equivalent conductances of two ions at infinite dilution in water at 25°C are given below

          $$\begin{gathered} {\mathrm{\Lambda }}_{{\mathrm{Ba}}^{2+}}^{°}= 127.00 {\mathrm{Scm}}^2/\mathrm{equiv}. \\ {\mathrm{\Lambda }}_{{\mathrm{Cl}}^{-}}^{°} = 76.00 {\mathrm{Scm}}^2/ \mathrm{equiv}. \end{gathered}$$

The equivalent conductance (in Scm²/equiv) of BaCl₂ at infinite dilution will be

• 203

• 279

• 205.5

• 139.5

The EMF of the cell,

Mg | Mg²+(0.01M) || Sn²⁺(0.1M)| Sn at 298K is $({\mathrm{E}}_{{\mathrm{Mg}}^{2+}/\mathrm{Mg}}^{°}= -2.34 \mathrm{V}, {\mathrm{E}}_{{\mathrm{Sn}}^{2+}/\mathrm{Sn}}^{°}= -0.14\mathrm{V})$

• 2.17 V

• 2.23V

• 2.51 V

• 2.45 V

The equivalent conductance at infinite dilution of a weak acid such as HF

• can be determined by extrapolation of measurements on dilute solutions of HCl, HBr and HI

• can be determined by measurement on very dilute HF solutions

• can best be determined from measurements on dilute solutions of NaF, NaCl and HCl

• is an undefined quantity

58.

The number of Faradays needed to reduce 4 g equivalents of Cu²⁺to Cu metal will be

• 1

• 2

• 1/2

• 4

Which one of the following cells can convert chemical energy of H₂ and O₂ directly into electrical energy?

• Mercury cell

• Daniell cell

• Fuel cel

• Lead storage cell

$$\begin{gathered} \mathrm{For} \mathrm{the} \mathrm{following} \mathrm{cell} \mathrm{reaction}, \\ \mathrm{Ag}| {\mathrm{Ag}}^{+}| \mathrm{AgCl}| {\mathrm{Cl}}^{⊝}| {\mathrm{Cl}}_2, \mathrm{Pt} \\ ∆{\mathrm{G}}_{\mathrm{f}}^{°}\left(\mathrm{AgCl}\right)= -109 \mathrm{kJ}/\mathrm{mol} \\ ∆{\mathrm{G}}_{\mathrm{f}}^{°}\left({\mathrm{Cl}}^{⊝}\right)= -129 \mathrm{kJ}/\mathrm{mol} \\ ∆{\mathrm{G}}_{\mathrm{f}}^{°}\left({\mathrm{Ag}}^{+}\right)= 78 \mathrm{kJ}/\mathrm{mo}/ \end{gathered}$$

E$°$ of the cell is

• - 0.60 V

• 0.60 V

• 6.0 V

• None of these