JEE Advanced2012ChemistryElectrochemistryActual
The electrochemical cell shown below is a concentration cell. M M ²⁺ (saturated solution of a sparingly soluble salt, . MX ₂ ) | M ^ 2 (0.001 ~mol dm ⁻³ ) M . The emf of the cell depends on the difference in concentrations of M ²⁺ ions at the two electrodes. The emf of the cell at 298 ~K is 0.059 ~V . Question: The solubility product ( K _ s p ; mol ³ dm ⁻⁹ ) of MX ₂ at 298 ~K based on the information available for t
Options
- A1 10⁻¹⁵
- B4 10⁻¹⁵
- C1 10⁻¹²
- D4 10⁻¹²
Correct answer
B. 4 10⁻¹⁵
Step-by-step solution
M M²⁺ (aq) | M²⁺ (aq) M0.001 M Anode : M M²⁺( aq )+2 e⁻ Cathode : M²⁺( aq )+2 e⁻ MM²⁺( aq )_ c M²⁺( aq )_ a array c E_ cell =0- 0.059 2 M²⁺( aq )_ a 10⁻³ 0.059=- 0.059 2 M²⁺( aq )_ a 10⁻³ -2= M²⁺( aq )_ a 10⁻³ array 10⁻² 10⁻³= M ²⁺( aq )_ a = solubility =s M X₂ M²⁺+2 X⁻K_ s p =S .(2 S)² 2 S K_ s p =4 s³=4 (10⁻⁵ )³=4 10⁻¹⁵