41. An electrochemical cell can behave like an electrolytic cell when _________.

A. $${E_{{\text{cell}}}} = 0$$
B. $${E_{{\text{cell}}}} > {E_{{\text{ext}}}}$$
C. $${E_{{\text{ext}}}} > {E_{{\text{cell}}}}$$
D. $${E_{{\text{cell}}}} = {E_{{\text{ext}}}}$$
Answer :   $${E_{{\text{ext}}}} > {E_{{\text{cell}}}}$$
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42. In a cell reaction, $$C{u_{\left( s \right)}} + 2Ag_{\left( {aq} \right)}^ + \to Cu_{\left( {aq} \right)}^{2 + } + 2A{g_{\left( s \right)}}$$
$$E_{{\text{cell}}}^ \circ = + 0.46\,V.$$    If the concentration of $$C{u^{2 + }}$$  ions is doubled then $$E_{{\text{cell}}}^ \circ $$  will be

A. doubled
B. halved
C. increased by four times
D. unchanged
Answer :   unchanged
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43. Match the column I with column II and mark the appropriate choice.
Column I Column II
a. Kohlrausch's law 1. $$\Lambda _{eq}^ \circ = \Lambda _c^ \circ + \Lambda _a^ \circ $$
b. Molar conductivity 2. $${\Lambda _m} = \frac{\kappa }{C}$$
c. Degree of dissociation 3. $$\alpha = \frac{{{\Lambda _m}}}{{\Lambda _m^ \circ }}$$
d. Dissociation constant 4. $${K_a} = \frac{{C{\alpha ^2}}}{{1 - \alpha }}$$

A. a - 3, b - 4, c - 1, d - 2
B. a - 1, b - 2, c - 3, d - 4
C. a - 4, b - 1, c - 2, d - 3
D. a - 2, b - 3, c - 4, d - 1
Answer :   a - 1, b - 2, c - 3, d - 4
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44. What will be the $$emf$$  for the given cell $$Pt\left| {{H_2}\left( {{P_1}} \right)\left| {{H^ + }\left( {aq} \right)} \right.} \right|\,\left| {{H_2}\left( {{P_2}} \right)} \right|Pt$$

A. $$\frac{{RT}}{F}{\log _e}\frac{{{P_1}}}{{{P_2}}}$$
B. $$\frac{{RT}}{{2F}}{\log _e}\frac{{{P_1}}}{{{P_2}}}$$
C. $$\frac{{RT}}{F}{\log _e}\frac{{{P_2}}}{{{P_1}}}$$
D. None of these.
Answer :   $$\frac{{RT}}{{2F}}{\log _e}\frac{{{P_1}}}{{{P_2}}}$$
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45. Consider the following $${E^ \circ }$$ values
$${E^o}_{\frac{{F_e^{3 + }}}{{F{e^{2 + }}}}} = + 0.77V;\,{E^o}_{\frac{{S{n^{2 + }}}}{{Sn}}} = - 0.14V$$
Under standard conditions the potential for the reaction
$$S{n_{\left( s \right)}} + 2F{e^{3 + }}_{\left( {aq} \right)} \to $$     $$2F{e^{2 + }}\left( {aq} \right) + S{n^{2 + }}\left( {aq} \right)$$     is

A. 0.91 $$V$$
B. 1.40 $$V$$
C. 1.68 $$V$$
D. 0.63 $$V$$
Answer :   0.91 $$V$$
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46. Which of the following is the cell reaction that occurs when the following half-cells are combined?
$${I_2} + 2{e^ - } \to 2{I^ - }\left( {1\,M} \right);$$     $${E^ \circ } = + 0.54\,V$$
$$B{r_2} + 2{e^ - } \to 2B{r^ - }\left( {1\,M} \right);$$     $${E^ \circ } = + 1.09\,V$$

A. $$2B{r^ - } + {I_2} \to B{r_2} + 2{I^ - }$$
B. $${I_2} + B{r_2} \to 2{I^ - } + 2B{r^ - }$$
C. $$2{I^ - } + B{r_2} \to {I_2} + 2B{r^ - }$$
D. $$2{I^ - } + 2B{r^ - } \to {I_2} + B{r_2}$$
Answer :   $$2{I^ - } + B{r_2} \to {I_2} + 2B{r^ - }$$
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47. How long would it take to deposit $$50\,g$$  of $$Al$$  from an electrolytic cell containing $$A{l_2}{O_3}$$  using a current of 105 ampere?

A. 1.54$$\,h$$
B. 1.42$$\,h$$
C. 1.32$$\,h$$
D. 2.15$$\,h$$
Answer :   1.42$$\,h$$
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48. For a cell reaction involving a two-electron change, the standard e.m.f. of the cell is found to be $$0.295\,V$$  at $${25^ \circ }C.$$ The equilibrium constant of the reaction at $${25^ \circ }C$$  will be

A. $$29.5 \times {10^{ - 2}}$$
B. $$10$$
C. $$1 \times {10^{10}}$$
D. $$1 \times {10^{ - 10}}$$
Answer :   $$1 \times {10^{10}}$$
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49. In the electrolytic cell, flow of electrons is from

A. Cathode to anode in solution
B. Cathode to anode through external supply
C. Cathode to anode through internal supply
D. Anode to cathode through internal supply
Answer :   Cathode to anode through internal supply
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50. When water is added to an aqueous solution of an electrolyte, what is the change in specific conductivity of the electrolyte?

A. Conductivity decreases
B. Conductivity increases
C. Conductivity remains same
D. Conductivity does not depend on number of ions.
Answer :   Conductivity decreases
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