Electrolysis problems
Answers are for parents and teachers.
1
A 720 g solution of 10 % Na₂SO₄ is electrolysed until it is 20 %. How many equivalents of electricity have passed?
40
2
A current of 10 A flows for 19 300 s through CuSO₄ solution. How many grams of H₂SO₄ (E = 49) form?
98
3
5·96 500 C (5 mol of electrons) passes through a solution containing 3 mol of CuSO₄. How many grams of Cu are deposited at the cathode (E = 32)?
160
4
3·96 500 C (3 mol of electrons) passes through a solution containing 1 mol of AgNO₃. What is the total mass in grams of Ag and H₂ released at the cathode?
110
5
Why does the solution become more acidic during the electrolysis of CuSO₄ solution?
Water is oxidised at the anode, forming H⁺, and H₂SO₄ accumulates in the solution.