MHT CET202520 Apr 2025Evening ShiftChemistryElectrochemistryActual
Which from following statement is correct regarding emf of cell for the cell reaction, Cd _ ( s ) + Cu _ ( aq ) ⁺² Cd _ ( aq ) ⁺²+ Cu _ ( s ) if concentration of Cd ⁺² is 10 times greater than concentration of Cu _ ( aq ) ⁺² at 298 K ?
Options
- Agreater than E _ cell ^ by 0.0592 V
- Bless than E^ _ cell by 0.0592 V
- Cgreater than E _ cell ^ by 0.0296 V
- Dless than E ^ _ cell by 0.0296 V
Correct answer
D. less than E ^ _ cell by 0.0296 V
Step-by-step solution
The cell reaction is: Cd _ ( s ) + Cu _ ( aq ) ⁺² Cd _ ( aq ) ⁺² + Cu _ ( s ) Applying the Nernst equation at 298 K: E_ cell = E_ cell ^ - 0.0592 n Q Two electrons are transferred, so n = 2 . The reaction quotient is Q = [ Cd ⁺²] [ Cu ⁺²] . Given that [ Cd ⁺²] = 10 [ Cu ⁺²] , substitution yields Q = 10 . Substituting n=2 and Q=10 : E_ cell = E_ cell ^ - 0.0592 2 (10) Since (10) = 1 : E_ cell = E_ cell ^ - 0.0296 V Thus, E_ cell is less than E_ cell ^ by 0.0296 V. The correct option is D .