At 298 K the molar conductivities at infinite dilution (${\mathrm{\Lambda }}_{\mathrm{m}}^{°}$) of NH₄Cl, KOH and KCl are 152.8, 272.6 and 149.8 S cm² mol^-1respectively. The ${\mathrm{\Lambda }}_{\mathrm{m}}^{°}$ of NH₄OH in Scm² mol^-1 and % dissociation of 0.01 M NH₄OH with ${\mathrm{\Lambda }}_{\mathrm{m}}$= 25.1 S cm² mol^-1 at the same temperature are

• 275.6, 0.91

• 275.6, 91

• 266.6, 96

• 30, 84

The products obtained at the cathode and anode respectively during the electrolysis of aqueous K₂SO₄ solution using platinum electrodes are

• O₂, H₂

• H₂, O₂

• H₂, SO₂

• K₂, SO₂

Same amount of electricity is passed through aqueous solutions of AgNO₃ and CuSO₄. The number of Ag and Cu atoms deposited are x and y respectively. The correct  relationship between x and y is

• x <y 

• x= 2y

• x = y

• y = 2x

In the acidic solution of copper sulphate and alkaline solution of copper cyanide respectively same electric current is flown for a definite time, which of the following statement is correct for this?

• Amount of copper deposited in both the solution is the same

• Amount of copper deposited in alkaline copper cyanide solution is less

• Amount of copper deposited in acidic copper sulphate solution is less

• None of the above

What is the emf of the cell, whose half cells are given below

Mg²⁺ + 2e^- → Mg(s) E =-2.37 V

Cu²⁺ + 2e^- → Cu(s) E =+0.34 V

• -2.30V

• 1.336V

• 2.17V

• 2.93V

Zn | $\underset{\mathrm{C} = 1}{{\mathrm{Zn}}^{2+}} \left|\right| \underset{\mathrm{C} = 1}{{\mathrm{Cu}}^{2+}}$ | Cu

If the standard reduction potential of zinc electrode and copper half cell is -0.76 V and 0.34 V respectively then the emf will be

• 1.1 V

• 1.4 V

• 1.34 V

• None of these

Rusting on iron needs

• dry air

• air and water

• distilled water and carbon dioxide

• oxygen and carbon dioxide

488.

In galvanic cell, the salt bridge is used to

• complete the circuit

• reduce the electric resistance in the cell

• separate cathode from anode

• carry salts for the chemical reaction

A cell, with cell constant 0.4 cm^-1, has the resistance of 40 ohm of a 0.01 M solution of an electrolyte, then the molar conductivity in ohm^-1 cm² mol^-1 will be

• 10⁴

• 10³

• 10²

• 1

If the standard elelctrode potential for the cell Zn | Zn²⁺ (aq) || Cu²⁺ (aq) | Cu is 1.10 V, then the maximum work done by this cell will be

• -106.15 kJ

• -212.30 kJ

• -318.45 kJ

• -424.60 kJ