The specific conductance of 0.01 M solution of a weak monobasic acid is 0.20 x 10-3 S cm-1. The dissociation constant of the acid is-
[Given = 400 S ]
| 1. | \(5 \times 10^{-2}\) | 2. | \(2.5 \times 10^{-5}\) |
| 3. | \(5 \times 10^{-4}\) | 4. | \(2.2 \times 10^{-11}\) |
Equivalent conductance of saturated \(\mathrm {BaSO}_4\) solution is \(400 \mathrm { ~ohm}^{-1}\) \(\mathrm {cm}^2\) \(\mathrm { ~equivalent}^{-1}\) and it's specific conductance is \(8 \times 10^{-5} \text { ohm}^{-1} \text {cm}^{-1}\) ; hence solubility product \(K_{sp}\) of \(\mathrm {BaSO}_4\) is :
1. \(4 \times 10^{-8} \text {M}^2\)
2. \(1 \times 10^{-8} \text {M}^2\)
3. \(2 \times 10^{-4} \text {M}^2\)
4. \(1 \times 10^{-4} \text {M}^2\)
Aluminium metal can be produced by the electrolysis of molten aluminium oxide at about 1000 °C.
The cathode reaction is: \(Al^{3 +} + 3 e^{-} \rightarrow Al\)
Given that the atomic mass of aluminium is 27 amu and 1 Faraday = 96,500 C, calculate the quantity of electricity (in coulombs) required to produce 5.12 kg of aluminium by this method:
1. \(5 . 49 \times 10^{1 } C\) of electricity
2. \(5 . 49 \times 10^{4 } C\) of electricity
3. \(1 . 83 \times 10^{7 } C\) of electricity
4. \(5 . 49 \times 10^{7 } C\) of electricity
Calculate the standard cell potential, E°cell, in volts and the standard Gibbs free-energy change, ΔG°, in kJ mol⁻¹, respectively, for a two-electron redox reaction at 298 K having an equilibrium constant of 3.8 × 10⁻³.
| 1. | -0.071, -13.8 | 2. | -0.071, 13.8 |
| 3. | 0.71, -13.8 | 4. | 0.071, -13.8 |
The specific conductance (K) of 0.02 M aqueous acetic acid solution at 298 K is S . The degree of dissociation of acetic acid is [Given: Equivalent conductance at infinite dilution of = 349.1 S and = 40.9 S )
1. 0.021
2. 0.21
3. 0.012
4. 0.12
For the Cell \(\mathrm{Pt(s)|| Br^-(aq)(0.010M)| Br_2(l)|| H^+(aq) (0.030M) |H_2(g) (1 bar) | Pt(s)}\)
If the concentration of becomes 2 times and the concentration of becomes half of the initial value, then emf of the cell is:
1. Doubles
2. Four times
3. Eight times
4. Remains the same
Limiting molar conductivities, for the given solutions, are:
\(\lambda_{m}^{0} \left(\right. H_{2} S O_{4} \left.\right) = x\) \(S c m^{2}\) \(m o l^{- 1}\)
\(\lambda_{m}^{0} \left(\right. K_{2} S O_{4} \left.\right) = y\) \(S c m^{2}\) \(m o l^{- 1}\)
\(\lambda_{m}^{0} \left(\right. C H_{3} C O O K \left.\right) = z\) \(S c m^{2}\) \(m o l^{- 1}\)
From the data given above, it can be concluded that \(\lambda_m^0 \) in (\(S\ cm^2\ mol^{-1}\)) for CH3COOH will be:
| 1. | \(\mathrm{x-y+2z}\) | 2. | \(\mathrm{x+y+z}\) |
| 3. | \(\mathrm{x-y+z}\) | 4. | \(\mathrm{{(x-y) \over 2}+z}\) |
The potential of a hydrogen electrode having a pH = 10 is :
1. 0.59 V
2. –0.59 V
3. 0.0 V
4. –5.9 V
Calculate the emf of the given cell:
Zn(s) | Zn+2 (0.1M) || Sn+2 (0.001M) | Sn(s)
(Given
1. 0.62 V
2. 0.56 V
3. 1.12 V
4. 0.31 V
The electrode potential of Cu electrode dipped in 0.025 M CuSO4 solution at 298 K is:
(standard reduction potential of Cu = 0.34 V)
1. 0.047 V
2. 0.293 V
3. 0.35 V
4. 0.387 V