0 votes
30 views
ago in ElectroChemistry by (390 points)
Calculate the resistance of a electrochemical cell at 25°C if the standard reduction potential of the anode is -1.36 V and the standard reduction potential of the cathode is +0.40 V. The solution contains 0.1 M CuSO4 and 0.01 M ZnSO4. The distance between the two electrodes is 5 cm and the cross-sectional area of each electrode is 2.5 cm².

1 Answer

0 votes
ago by (430 points)
To calculate the resistance of the electrochemical cell, we first need to determine the cell potential  E_cell  using the Nernst equation. The Nernst equation is given by:E_cell = E_cell -  RT/nF  * ln Q where:E_cell = standard cell potentialR = gas constant  8.314 J/molK T = temperature in Kelvin  25C = 298.15 K n = number of electrons transferred in the redox reactionF = Faraday's constant  96485 C/mol Q = reaction quotientFirst, we need to find the standard cell potential  E_cell . This can be calculated by subtracting the standard reduction potential of the anode from the standard reduction potential of the cathode:E_cell = E_cathode - E_anodeE_cell = 0.40 V -  -1.36 V E_cell = 1.76 VNext, we need to determine the number of electrons transferred in the redox reaction  n . In this case, both Cu and Zn are involved in a two-electron transfer process:Cu + 2e  Cu  reduction Zn  Zn + 2e  oxidation So, n = 2.Now, we need to calculate the reaction quotient  Q . The reaction quotient is given by:Q = [Zn]/[Cu]Using the given concentrations of CuSO and ZnSO:Q =  0.01 M / 0.1 M Q = 0.1Now we can plug all the values into the Nernst equation:E_cell = 1.76 V -  8.314 J/molK * 298.15 K / 2 * 96485 C/mol  * ln 0.1 E_cell  1.76 V - 0.0296 VE_cell  1.7304 VNow that we have the cell potential, we can calculate the resistance of the electrochemical cell using Ohm's law:V = IRwhere:V = voltage  E_cell I = currentR = resistanceIn this case, we don't have the current  I  value. However, we can still express the resistance  R  in terms of the cell potential  E_cell  and current  I :R = V/IR = E_cell/IWithout the current value, we cannot calculate the exact resistance of the electrochemical cell. However, we have determined the cell potential  E_cell  to be approximately 1.7304 V, which can be used to calculate the resistance once the current value is known.

Related questions

Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...