The $\Delta \mathrm{G}^{\circ}$ for the reaction, $C d^{2+}(a q)+Z n(s) \rightarrow Z n^{2+}(a q)+C d(s)$ is:

$$ \begin{aligned} &\text { Using the data given below, the strongest reducing agent is: }\\ &\begin{array}{ll} \mathrm{E}_{\mathrm{Cr}_2 \mathrm{O}_7}^{\mathrm{o}}{ }^{2-} / \mathrm{Cr}^{3+}=1.33 \mathrm{~V} & \mathrm{E}_{\mathrm{MnO}_4^{-} / \mathrm{Mn}^{2+}}^{\mathrm{o}}=1.51 \mathrm{~V} \\ \mathrm{E}_{\mathrm{Cl}_2 / \mathrm{Cl}^{-}}^{\mathrm{O}}=1.36 \mathrm{~V} & \mathrm{E}_{\mathrm{Cr}^{3+} / \mathrm{Cr}}^{\mathrm{O}}=-0.74 \mathrm{~V} \end{array} \end{aligned} $$

Consider a Galvanic cell in which the following reactions occurs: $\mathrm{Fe}^{2+}(\mathrm{aq})+\mathrm{Ag}^{+}(\mathrm{aq}) \rightarrow \mathrm{Fe}^{3+}(\mathrm{aq})+\mathrm{Ag}(\mathrm{s})$. What is the standard potential of the cell? Given: $\mathrm{E}^0\left(\mathrm{Ag}^{+} / \mathrm{Ag}\right)=\mathrm{aV} \quad \mathrm{E}^0\left(\mathrm{Fe}^{2+} / \mathrm{Fe}\right)=\mathrm{bV} \quad \& \quad \mathrm{E}^0\left(\mathrm{Fe}^{3+} / \mathrm{Fe}\right)=\mathrm{cV}$

Identify the correct mathematical expression which represents the variation in molar conductivity of a weak acid having concentration C and ionisation constant $\mathrm{K}_{\mathrm{a}}$

( $\lambda_m^{\infty}=$ molar conductivity at infinite dilution, $\lambda_{\mathrm{m}}=$ molar conductivity at concentration C )