Q. No.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
(\(\mathrm{\mathrm{\Lambda_{CH_{3}COO^{-}}^{o} \ = \ 50 \ S \ cm^{2} \ mol^{-1} }}\))
1. mol L-1
The molar conductance of NaCl, HCI, and CH3COONa at infinite dilution are 126.45, 426.16, and 91.0 S cm mol-1 respectively. The molar conductance of CH3COOH at infinite dilution will be:
1. 698.28 S cm2 mol-1
2. 540.48 S cm2 mol-1
3. 201.28 S cm2 mol-1
4. 390.71 S cm2 mol-1
In a typical fuel cell, the reactants (R) and products (P) are:
| 1. | R = H2(g), O2(g); P = H2O2(l) |
| 2. | R = H2(g), O2(g); P = H2O(l) |
| 3. | R = H2(g) , O2(g) , C l2(g) ; P = HClO4(aq) |
| 4. | R = H2(g) , N2(g) ; P = NH3(aq) |
\(\mathrm{MnO}_{4}^{-}+8 \mathrm{H}^{+}+5 \mathrm{e}^{-} \rightarrow \mathrm{Mn}^{2+}+4 \mathrm{H}_{2} \mathrm{O}, \)
\( \mathrm{E}_{\mathrm{Mn}^{2+}}^{\circ} / \mathrm{MnO}_{4}^{-}=-1.510 \mathrm{~V} \)
\( \frac{1}{2} \mathrm{O}_{2}+2 \mathrm{H}^{+}+2 \mathrm{e}^{-} \rightarrow \mathrm{H}_{2} \mathrm{O}, \)
\( \mathrm{E}_{\mathrm{O}_{2} / \mathrm{H}_{2} \mathrm{O}}^{\circ}=+1.223 \mathrm{~V}\)
Will the permanganate ion, \(\mathrm{MnO}_{4}^{-}\) , liberate \(\mathrm{O}_{2}\) from water in the presence of an acid?
1. No, because \(\mathrm{E}_{\text {cell }}^{\circ}=-2.733 \mathrm{~V}\)
2. Yes, because \(\mathrm{E}_{\text {cell }}^{\circ}=+0.287 \mathrm{~V}\)
3. No, because \(\mathrm{E}_{\text {cell }}^{\circ}=-0.287 \mathrm{~V}\)
4. Yes, because \(\mathrm{E}_{\text {cell }}^{\circ}=+2.733 \mathrm{~V}\)
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 |
(F represents the charge on 1 mole of electrons.)
| 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 \(CH_3COONa \) 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 |
Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)
is 1.1 V. Calculate the standard Gibbs energy change for the cell reaction.
(Given F = 96487 C mol-1)
| 1. | –200.27 kJ mol-1 | 2. | –212.27 kJ mol-1 |
| 3. | –212.27 J mol-1 | 4. | –200.27 J mol-1 |
| Assertion (A): | In equation \(\Delta_{\mathrm{r}} \mathrm{G}=-\mathrm{nFE} _{\text {cell }}, \) value \(\Delta_rG \) depends on n. |
| Reason (R): | \(E_{cell} \) is an intensive property and \(\Delta_rG \) is an extensive property. |
In the light of the above statements choose the correct answer from the options given below:
| 1. | (A) is False but (R) is True. |
| 2. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 3. | Both (A) and (R) are True and (R) is not the correct explanation of (A). |
| 4. | (A) is True but (R) is False. |
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