At 25 °C molar conductance of 0.1 molar aqueous solution of ammonium hydroxide is 9.54 Ω-1 cm2 mol-1 and at infinite dilution its molar conductance is 238 Ω-1 cm2 mol-1. The degree of ionisation of ammonium hydroxide at the same concentration and temperature is :
1. | 2.080 % | 2. | 20.800 % |
3. | 4.008 % | 4. | 40.800 % |
Which is the correct representation for Nernst equation ?
1. \(E_{\mathrm{RP}}=E_{\mathrm{RP}}^{\circ}+\frac{0.059}{\mathrm{n}} \log \frac{[\text { oxidant }]}{[\text { reductant }]}\)
2. \(E_{\mathrm{OP}}=E_{\mathrm{OP}}^{\circ}-\frac{0.059}{\mathrm{n}} \log \frac{[\text { oxidant }]}{[\text { reductant }]}\)
3. \(E_{\mathrm{OP}}=E_{\mathrm{OP}}^{\circ}+\frac{0.059}{\mathrm{n}} \log \frac{[\text { reductant }]}{[\text { oxidant }]}\)
4. All of the above
When a copper wire is immersed in a solution of AgNO3, the colour of the solution becomes blue because copper:
1. Forms a soluble complex with \(AgNO_3\)
2. Is oxidised to \(Cu^{2+}\)
3. Is reduced to \(Cu^{2-}\)
4. Splits up into atomic form and dissolves
The specific conductance of a 0.1 M KCl solution at 23 °C is 0.012 Ω–1 cm–1. The resistance of cells containing the solution at the same temperature was found to be 55 Ω. The cell constant will be:
1. | 0.142 cm–1 | 2. | 0.66 cm–1 |
3. | 0.918 cm–1 | 4. | 1.12 cm–1 |
Given below are two half-cell reactions:
Mn2+ + 2e- → Mn; E0 = -1.18V
2Mn3+ + 2e- → 2Mn2+; E0 = +1.51V
The E0 for 3Mn2+ → 2Mn+3 + Mn will be:
1. -2.69V; the reaction will not occur
2. -2.69V; the reaction will occur
3. -0.33V; the reaction will not occur
4. -0.33V; the reaction will occur
E0 for Fe2+ + 2e → Fe is –0.44 volt and E0 for Zn2+ + 2e→ Zn is –0.76 volt, thus:
1. Zn is more electropositive than Fe.
2. Fe is more electropositive than Zn.
3. Zn is more electronegative.
4. None of the above.
The voltage of the cell given below increases with:
Cell: Sn(s) + 2Ag+(aq) → Sn2+(aq) + 2Ag(s)
1. Increase in size of the silver rod.
2. Increase in the concentration of Sn2+ ions.
3. Increase in the concentration of Ag+ ions.
4. None of the above.
, the standard emf of the reaction
will be
1. 0.111V
2. 0.330V
3. 1.653V
4. 1.212V
The standard electrode potential for Sn4+/Sn2+ couple is +0.15 V and that for the Cr3+/Cr couple is -0.74 V. These two couples in their standard state are connected to make a cell. The cell potential will be:
1. | +0.89 V | 2. | +0.18 V |
3. | +1.83 V | 4. | +1.199 V |
If an iron rod is dipped in CuSO4 solution, then:
1. Blue colour of the solution turns red.
2. Brown layer is deposited on iron rod.
3. No change occurs in the colour of the solution.
4. None of the above.