ExamGOAL
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53
Subjective

Match the items of Column I and Column II.

Column I Column II
A. $\kappa$ 1. $I \times t$
B. $\wedge_m$ 2. $\wedge_m / \wedge^o_m$
C. $\alpha$ 3. $\frac{\kappa}{C}$
D. $Q$ 4. $\frac{G^*}{R}$

Explanation

A. $\rightarrow(4)$ B. $\rightarrow$ (3) C. $\rightarrow(2)$ D. $\rightarrow$ (1)

A. Conductivity $(\kappa)=\frac{G^*}{R}$

B. Molar conductivity $\left(\wedge_m\right)=\frac{\kappa}{C}$

C. Degree of dissociation $(\alpha)=\frac{\wedge_m}{\wedge_m^{\circ}}$

D. Charge $Q=I \times t$

where, $Q$ is the quantity of charge in coulomb when $I$ ampere of current is passed through an electrolyte for $t$ second.

54
Subjective

Match the items of Column I and Column II.

Column I Column II
A. Lechlanche cell 1. Cell reaction $2 \mathrm{H}_2+\mathrm{O}_2 \longrightarrow 2 \mathrm{H}_2 \mathrm{O}$
B. Ni-Cd cell 2. Does not involve any ion in solution and is used in hearing aids.
C. Fuel cell 3. Rechargeable
D. Mercury cell 4. Reaction at anode, $\mathrm{Zn} \longrightarrow \mathrm{Zn}^{2+}+2 e^{-}$
5. Converts energy of combustion into electrical energy

Explanation

A. $\rightarrow$ (4) B). $\rightarrow$ (3) C. $\rightarrow(1,5)$ D. $\rightarrow$ (2)

A. Lechlanche cell The electrode reaction occurs at Lechlanche cell are

At anode $\mathrm{Zn}(\mathrm{s}) \longrightarrow \mathrm{Zn}^2+2 \mathrm{e}^{-}$

At cathode $\mathrm{MnO}_2+\mathrm{NH}_4^{+}+e^{-} \longrightarrow \mathrm{MnO}(\mathrm{OH})+\mathrm{NH}_3$

B. Ni-Cd cell is rechargeable. So, it has more life time.

C. Fuel cell produces energy due to combustion. So, fuel cell converts energy of combustion into electrical energy e.g., $2 \mathrm{H}_2+\mathrm{O}_2 \longrightarrow 2 \mathrm{H}_2 \mathrm{O}$

D. Mercury cell does not involve any ion in solution and is used in hearing aids.

55
Subjective

Match the items of Column I and Column II on the basis of data given below

$$\begin{aligned} \mathrm{E}_{\mathrm{F}_2 / \mathrm{F}^{-}}^{\mathrm{s}} & =2.87 \mathrm{~V}, \mathrm{E}_{\mathrm{Li}^{+} / \mathrm{Li}}^{\mathrm{s}}=-3.5 \mathrm{~V}, \\ \mathrm{E}_{\mathrm{Au}^{3+} / \mathrm{Au}} & =1.4 \mathrm{~V}, \mathrm{E}_{\mathrm{Br}_2 / \mathrm{Br}^{-}}^{\mathrm{s}}=1.09 \mathrm{~V} \end{aligned}$$

Column I Column II
A. F$_2$ 1. Metal is the strongest reducing agent
B. Li 2. Metal ion which is the weakest oxidising agent
C. Au$^{3+}$ 3. Non-metal which is the best oxidising agent
D. Br$^{-}$ 4. Unreactive metal
E. Au 5. Anion that can be oxidised by Au$^{3+}$
F. Li$^{+}$ 6. Anion which is the weakest reducing agent
G. F$^-$ 7. Metal ion which is an oxidising agent

Explanation

A. $\rightarrow(3)$ B. $\rightarrow$ (1) C. $\rightarrow$ (7) D. $\rightarrow$ (5) E. $\rightarrow$ (4) F. $\rightarrow$ (2) G. $\rightarrow(6)$

A. $F_2$ is a non-metal and best oxidising agent because SRP of $F_2$ is +2.87 V .

B. Li is a metal and strongest reducing agent because SRP of Li is -3.05 V .

C. $\mathrm{Au}^{3+}$ is a metal ion which is an oxidising agent as SRP of $\mathrm{Au}^{3+}$ is +1.40 V .

D. $\mathrm{Br}^{-}$is an anion that can be oxidised by $\mathrm{Au}^{3+}$ as $\mathrm{Au}^{3+}\left(E^{\circ}=1.40\right)$ is greater than $$\mathrm{Br}^{-}\left(E^{\circ}=1.09 \mathrm{~V}\right)$$

E . Au is an unreactive metal.

F. $\mathrm{Li}^{+}$is a metal ion having least value of $\operatorname{SRP}(-3.05 \mathrm{~V})$, hence it is the weakest oxidising agent.

G. $\mathrm{F}^{-}$ is an anion which is the weakest reducing agent as $\mathrm{F}^{-} / \mathrm{F}_2$ has low oxidation potential $(-2.87 \mathrm{~V})$.

56
MCQ (Single Correct Answer)

Assertion (A) Cu is less reactive than hydrogen.

Reason $(R) \mathrm{E}_{\mathrm{Cu}^{2+} / \mathrm{Cu}}^{\mathrm{S}}$ is negative.

A
Both assertion and reason are true and the reason is the correct explanation of assertion.
B
Both assertion and reason are true and reason is not the correct explanation of assertion.
C
Assertion is true but the reason is false.
D
Both assertion and reason are false.
E
Assertion is false but the reason is true.
57
MCQ (Single Correct Answer)

Assertion (A) $\mathrm{E}_{\text {cell }}$ should have a positive value for the cell to function.

Reason (R) $\mathrm{E}_{\text {cathode }}<\mathrm{E}_{\text {anode }}$

A
Both assertion and reason are true and the reason is the correct explanation of assertion.
B
Both assertion and reason are true and reason is not the correct explanation of assertion.
C
Assertion is true but the reason is false.
D
Both assertion and reason are false.
E
Assertion is false but the reason is true.