We’re being asked to calculate the number of moles of Cl2 gas evolved from the oxidation of Cl-.
• current = 0.5 A
▪ Note that amperes (A) = charge/time = C/s
▪ Current = 0.5 C/s
• t = 30 minutes
▪ Since current is in C/s, we will have to convert time from min to s
• Faraday’s constant = 96,485 C/(mol e-)
▪ Constant found in books or on the internet
Let’s first determine how many electrons are involved when Cl2 is generated from the reaction:
A current of 0.5 amp flows through an electrochemical cell that evolves Cl 2 gas by the oxidation of Cl1-. What number of moles of Cl 2 gas are generated in a period of 30 min?
A) 900 mole
B) 9.3 x10-3 mole
C) 4.6 x10-3 mole
D) 1.6 x 10-4 mole
E) 7.8 x 10-5 mole