Question

What is the efficiency of an electrochemical cell with a standard potential of 1.5V when the measured potential is 1.2V and the current passing through the cell is 0.5A for 2 hours? (Assume the cell is operating under standard conditions.)

Answer 1

To calculate the efficiency of an electrochemical cell, we need to compare the actual output energy to the theoretical maximum energy output. First, we need to find the actual output energy and the theoretical maximum energy output.Actual output energy  E_actual  can be calculated using the formula:E_actual = V_actual * I * twhere V_actual is the measured potential  1.2V , I is the current  0.5A , and t is the time in seconds  2 hours * 3600 seconds/hour = 7200 seconds .E_actual = 1.2V * 0.5A * 7200s = 4320 JoulesThe theoretical maximum energy output  E_theoretical  can be calculated using the formula:E_theoretical = V_theoretical * I * twhere V_theoretical is the standard potential  1.5V , I is the current  0.5A , and t is the time in seconds  7200 seconds .E_theoretical = 1.5V * 0.5A * 7200s = 5400 JoulesNow, we can calculate the efficiency of the electrochemical cell using the formula:Efficiency =  E_actual / E_theoretical  * 100%Efficiency =  4320 Joules / 5400 Joules  * 100% = 0.8 * 100% = 80%The efficiency of the electrochemical cell is 80%.