An aqueous solution of copper sulphate is subjected to electrolysis using platinum electrodes. Calculate the number of electrons flowing through the circuit when 0.3175 g of copper is deposited. Also calculate the number of molecules present in anodic product (atomic mass of copper = 63.5)

An aqueous solution of copper sulphate is subjected to electrolysis us

1.	An aqueous solution of copper sulphate is subjected to electrolysis using platinum electrodes. Calculate the number of electrons flowing through the circuit when 0.3175 g of copper is deposited. Also calculate the number of molecules present in anodic product (atomic mass of copper = 63.5)
Answer» Solution :`CuSO_(4) + Cu^(2+) + So_(4)^(-2)` `H_(2)O rarr H^(+) + OH^(-)` Among the cations `Cu^(+2) and H^(+), Cu^(+2)` requires lesser discharge potential compared to `H^(+)` so Cu is discharged at cathode. At cathode : `Cu^(+2) + 2e^(-) rarr Cu` For the deposition of 63.5 g of Cu, `2 XX 6.023 xx 10^(23) e^(-)` have to flow through the circuit, THEREFORE, 0.3175 g of Cu requires ? electrons `= (0.3175 xx 2 xx 6.023 xx 10^(23))/(63.5)` `= 6.023 xx 10^(21)` electrons are required AT ANODE : `4OH^(-) rarr 2H_(2)O + 4e^(-) + O_(2)` For the formation of 1 mole of oxygen 4 moles of electrons are required `96,500 C = (N)/(4)` moles of oxygen `= (6.023 xx 10^(23))/(4)` molecule (`6 xx 10^(21)` electrons = 965 C) No. of molecules of oxygen liberated for 965 C `= (965 xx 6.023 xx 10^(23))/(4 xx 96,500) = 1.5 xx 10^(21)` molecules