Cell potential and Gibbs energy
- Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R :Assertion A : In equation Δ_r G = -nFE_cell, value of Δ_r G depends on n.Reasons R : E_cell is an intensive property and Δ_r G is an extensive prop… Answer: 2. Both A and R are true and R is the correct explanation of A. Key idea: Δ_rG = -nFE_cell links an extensive quantity to an intensi... 1
- For a cell involving one electron E^_cell = 0.59 V at 298 K, the equilibrium constant for the cell reaction is :[Given that 2.303 RT/F = 0.059 V at T = 298 K] Answer: 3. 1.0×10¹⁰ At 298 K, E^(ominus)_cell = 0.059/nlog K . log K = dfracnE^(ominus)0.059 = 1×0.59/0.059 = 10 , so K = 1.0×10¹⁰ . Option... 1
- For the cell reaction2Fe^3+(aq) + 2I^-(aq) → 2Fe^2+(aq) + I_2(aq)E^_cell = 0.24 V at 298 K. The standard Gibbs energy (Δ_rG^) of the cell reaction is :[Given that Faraday constant F = 96500 C mol^-1] Answer: 1. -46.32 kJ mol ⁻¹ Formula: Δ_rG^(ominus) = -nFE^(ominus)_cell . In the reaction 2mathrmFe³⁺ + 2I^- → 2mathrmFe²⁺ + I₂ , 2 electron... 1
- If the E^°_cell for a given reaction has a negative value, which of the following gives the correct relationships for the values of Δ G^° and K_eq? Answer: 4. Δ G^° > 0 ; K_eq < 1 Key idea: Δ G^°=-nFE^°_cell=-RTln K . If E^°_cell<0 , then Δ G^°>0 , so ln K<0 and K_eq<1 . The reaction is... 1