Final answer:
The volume of H2 gas collected at the cathode during the electrolysis is approximately 9.126 L, and the volume of O2 gas collected at the anode is approximately 4.563 L, given a current of 10 amperes for 2 hours at 25°C and 1.00 atm.
Step-by-step explanation:
To calculate the volume of H2 and O2 gases collected at the cathode and anode respectively during the electrolysis of an aqueous solution of Na2SO4, we first need to determine the amount of charge passed through the solution.
Since the current is 10 amperes and the electrolysis goes on for 2 hours, the total charge Q is given by Q = current × time = 10 A × 2 h × 3600 s/h = 72000 C.
Using Faraday's laws of electrolysis, the amount of a substance produced at an electrode is directly proportional to the quantity of electricity that passes through the electrolyte.
The Faraday constant is approximately 96500 C/mol, which is the charge required to produce one mole of a monovalent ion.
For hydrogen at the cathode (which is produced in a 2:1 ratio to electrons):
- n(H2) = Q / (2 × F) = 72000 C / (2 × 96500 C/mol) = 0.373 mol
For oxygen at the anode (which is produced in a 4:1 ratio to electrons since it takes 4 electrons to produce an O2 molecule):
- n(O2) = Q / (4 × F) = 72000 C / (4 × 96500 C/mol) = 0.1865 mol
Using the ideal gas law (PV=nRT), with P=1 atm, T = 25°C (which is 298 K), and R = 0.0821 L·atm/(K·mol), we can calculate the volume of each gas.
Volume of H2 (V = nRT/P):
- V(H2) = (0.373 mol) × (0.0821 L·atm/(K·mol)) × (298 K) / (1 atm) ≈ 9.126 L
Volume of O2 (V = nRT/P):
- V(O2) = (0.1865 mol) × (0.0821 L·atm/(K·mol)) × (298 K) / (1 atm) ≈ 4.563 L