Metals have conductivity of the order of (ohm-1 m-1):-

1. 1012

2. 108

3. 102

4. 10-6
 

Subtopic:  Conductance & Conductivity |
Level 3: 35%-60%
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The electrochemical cell is represented as:

Pt | H₂(1 atm) | HCl (0.1 M) || CH₃COOH (0.1 M) | H₂(1 atm) | Pt

The EMF of the cell will not be zero because:

1. EMF depends only on the molarities of the acids used

2. The pH of 0.1 M HCl and 0.1 M CH₃COOH is different

3. Temperature remains constant in both half-cells

4. Different acids are present in the two half-cells

Subtopic:  Electrode & Electrode Potential |
 55%
Level 3: 35%-60%
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Saturated solution of KNO3 is used to make 'salt-bridge' because:

1. velocity of K+ is greater than that of NO3-

2. velocity of NO3- is greater than that of K+

3. Velocities of both K+ and NO3- are nearly the same

4. KNO3 is highly soluble in water

Subtopic:  Batteries & Salt Bridge |
 75%
Level 2: 60%+
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A current is passed through two voltameters connected in series. The first voltmeter connected in series. The first voltmeter contains XSO4(aq) while the second voltmeter contains Y2SO4(aq). The relative  atomic masses of X and Y are in the ratio of 2:1. The ratio of the mass of X liberated to the mass of Y liberated is: 

1. 1:1

2. 1:2

3. 2:1

4. None of the above

Subtopic:  Faraday’s Law of Electrolysis |
Level 3: 35%-60%
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At 25 °C molar conductance of 0.1 molar aqueous solution of ammonium hydroxide is 9.54 Ω-1 cmmol-1 and at infinite dilution its molar conductance is 238 Ω-1 cmmol-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 %
Subtopic:  Conductance & Conductivity |
 78%
Level 2: 60%+
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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

Subtopic:  Nernst Equation |
Level 3: 35%-60%
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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

Subtopic:  Electrochemical Series |
 80%
Level 1: 80%+
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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
Subtopic:  Conductance & Conductivity |
 85%
Level 1: 80%+
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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

Subtopic:  Electrode & Electrode Potential |
 51%
Level 3: 35%-60%
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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.

Subtopic:  Electrode & Electrode Potential |
 64%
Level 2: 60%+
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