1
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

A current of 3.0A is passed through 750 ml of 0.45 M solution of CuSO$$_4$$ for 2 hours with a current efficiency of 90%. If the volume of the solution is assumed to remain constant, what would be the final molarity of CuSO$$_4$$ solution?

A
0.296
B
0.4
C
0.237
D
0.316
2
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

Arrange the following redox couples in the increasing order of their reducing strength:

$$\begin{array}{ll} {[\mathrm{A}]=\mathrm{Cu} / \mathrm{Cu}^{2+}} & \mathrm{E}^0=-0.34 \mathrm{~V} \\ {[\mathrm{~B}]=\mathrm{Ag} / \mathrm{Ag}^{+}} & \mathrm{E}^0=-0.8 \mathrm{~V} \\ {[\mathrm{C}]=\mathrm{Ca} / \mathrm{Ca}^{2+}} & \mathrm{E}^0=+2.87 \mathrm{~V} \\ {[\mathrm{D}]=\mathrm{Cr} / \mathrm{Cr}^{3+}} & \mathrm{E}^0=+0.74 \mathrm{~V} \end{array}$$

A
B < A < D < C
B
A < C < B < D
C
C < D < A < B
D
D < A < C < B
3
COMEDK 2024 Morning Shift
MCQ (Single Correct Answer)
+1
-0

What would be the EMF of the cell in which the following reaction occurs:

$$\begin{aligned} & \mathrm{Cd}(\mathrm{S})+2 \mathrm{H}^{+} \rightarrow \mathrm{Cd}^{2+}+\mathrm{H}_{2(\mathrm{~g})} \\ & {\left[\mathrm{H}^{+}\right]=0.02 \mathrm{M} \quad \mathrm{E}^0\left(\mathrm{Cd}^{2+} / \mathrm{Cd}\right)=-0.4 \mathrm{~V},\left[\mathrm{Cd}^{2+}\right]=0.01 \mathrm{M} \text { and partial pressure of } \mathrm{H}_2 \text { gas }=0.8 \mathrm{~atm} .} \end{aligned}$$

A
0.3020 V
B
0.4859 V
C
0.3616 V
D
0.4471 V
4
COMEDK 2024 Morning Shift
MCQ (Single Correct Answer)
+1
-0

Propane in presence of $$\mathrm{O}_2$$ gas undergoes complete combustion to produce $$\mathrm{CO}_2$$ and $$\mathrm{H}_2 \mathrm{O}$$. The required $$\mathrm{O}_2$$ for this combustion reaction was produced by the electrolysis of water. For what duration of time had water been electrolysed by passing $$200 \mathrm{~A}$$ current so that Oxygen gas produced could completely burn $$44 \mathrm{~g}$$ of Propane?

A
2.68 hours
B
1.98 hours
C
3.86 hours
D
1.34 hours
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