Statement 1: | The standard electrode potential of the system Mg2+ | Mg can be measured with respect to hydrogen electrode. |
Statement 2: | The standard electrode potential for hydrogen electrode is zero. |
Rusting of iron is envisaged as setting up of an electrochemical cell because:
1. Oxidation of iron takes place during rusting.
2. Reduction of iron takes place.
3. Iron shows disproportionation reaction.
4. Oxygen is getting oxidised.
For a cell reaction involving a two-electron change, the standard Emf of the cell is found to be 0.295V at 25oC . The equilibrium constant of the reaction at 25oC will be :
1. 1 \(\times\) 10-10
2. 29.5 \(\times\) 10-2
3. 10
4. 1 \(\times\) 1010
Find the emf of the cell in which the following reaction takes place at 298 K:
\(\mathrm{Ni}(\mathrm{s})+2 \mathrm{Ag}^{+}(0.001 \mathrm{M}) \rightarrow \mathrm{Ni}^{2+}(0.001 \mathrm{M})+2 \mathrm{Ag}(\mathrm{s}) \)
\( \small{\text { (Given that } \mathrm{E}_{\text {cell }}^{\circ}=10.5 \mathrm{~V}, \frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.059 \text { at } \ 298 \mathrm{~K})} \)
1. 1.05 V
2. 1.0385 V
3. 1.385 V
4. 0.9615 V
The three cells with their \(E^\circ_{\text{(cell)}}\) values are given below:
Cells | \(E^\circ_{\text{(cell)}}/V\) | |
(a) | Fe|Fe2+||Fe3+|Fe | 0.404 |
(b) | Fe|Fe2+||Fe3+, Fe2+|Pt | 1.211 |
(c) | Fe|Fe3+||Fe3+, Fe2+|Pt | 0.807 |
1. | –1.212 F, –1.211 F, –0.807 F |
2. | +2.424 F, +2.422 F, +2.421 F |
3. | –0.808 F, –2.422 F, –2.421 F |
4. | –2.424 F, –2.422 F, –2.421 F |
\(\land^o_m\) for NaCl, HCl and \(\mathrm{CH_3COONa }\) are 126.4, 425.9, and 91.05 S cm2 mol–1 respectively. If the conductivity of 0.001028 mol L–1 acetic acid solution is \(4.95 \times 10^{-5} S ~cm^{-1} \), the degree of dissociation of the acetic acid solution is-
1. | 0.01233 | 2. | 1.00 |
3. | 0.1233 | 4. | 1.233 |
Two half cell reactions are given below:
\(\begin{aligned} &\mathrm{Co}^{3+}+e^{-} \rightarrow \mathrm{Co}^{2+}, \mathrm{E}_{\mathrm{Co}^{2+} / \mathrm{Co}^{3+}}^{\circ}=-1.81 \mathrm{~V} \\ &2 \mathrm{Al}^{3+}+6 e^{-} \rightarrow 2 \mathrm{Al}(\mathrm{s}), \mathrm{E}_{\mathrm{Al} / \mathrm{Al}^{3+}}^{\circ}=+1.66 \mathrm{~V} \end{aligned} \)
The standard EMF of a cell with feasible redox reaction will be:
1. | +7.09 V | 2. | +0.15 V |
3. | +3.47 V | 4. | –3.47 V |
1. | –200.27 kJ mol–1 | 2. | –212.27 kJ mol–1 |
3. | –212.27 J mol–1 | 4. | –200.27 J mol–1 |
The molar conductivity of 0.007 M acetic acid is 20 S cm2 mol–1. The dissociation constant of acetic acid is :
(\(\mathrm{\Lambda_{H^{+}}^{o} \ = \ 350 \ S \ cm^{2} \ mol^{-1} }\))
(\(\mathrm{\mathrm{\Lambda_{CH_{3}COO^{-}}^{o} \ = \ 50 \ S \ cm^{2} \ mol^{-1} }}\))
1. mol L–1
2. mol L–1
3. mol L–1
4. mol L–1