Electrochemistry - Physical Chemistry - Chemistry Previous Year Questions

(A) Calculate \(\Delta_r G^\circ\) of the following reaction

$$A{g^ + }(aq.) + C{l^ - }(aq.) \to AgCl(s)$$

Given :

$$\mathrm{\Delta_r G^\circ(AgCl)\quad-109~kJ/mole}$$

$$\mathrm{\Delta_r G^\circ(Cl^-)\quad-129~kJ/mole}$$

$$\mathrm{\Delta_r G^\circ(Ag^+)\quad-77~kJ/mole}$$

(i) Represent the above reaction in form of a cell.

(ii) Calculate E\(^\circ\) of the cell.

(iii) Find \({\log _{10}}{K_{sp}}\) of AgCl.

(B) If \(6.539\times10^{-2}\) g of metallic Zn (amu = 65.39) was added to 100 mL of saturated solution of AgCl, then calculate \({\log _{10}} = {{[Z{n^{2 + }}]} \over {{{[A{g^ + }]}^2}}}\). Also find how many moles of Ag will be formed.

Given that :

$$\mathrm{Ag^++e^-\to Ag\quad E^\circ=0.80~V}$$

$$\mathrm{Zn^{2+}+2e^-\to Zn\quad E^\circ=-0.76~V}$$

At 300 K , the molar conductivities of the aqueous solutions of three salts at two different concentrations are given below :

The conductivity of a saturated aqueous solution of AgCl is $1.40 \times 10^{-6} \mathrm{~S} \mathrm{~cm}^{-1}$ at 300 K . If the solubility of AgCl in water at 300 K is $\boldsymbol{X} \mathrm{mol} \mathrm{L}^{-1}$, then $\log _{10}\left(\boldsymbol{X}^{-1}\right)$ is

(Assume that AgCl dissolved in water ionizes completely and that the molar conductivity of saturated AgCl solution is equal to its limiting molar conductivity.)