118.8cm2 surface of the copper cathode of a voltameter is to be coated with 10-6m thick copper of density 9 x 103kgm-3. How long will the process run with 1...

118.8cm2 surface of the copper cathode of a voltameter is to be coated with 10-6m thick copper of density 9 x 103kgm-3. How long will the process run with 10A constant current?

[3.3 x 10-7kgC-1]

Answer Details

The problem is asking for the time it will take to deposit a certain thickness of copper on a copper cathode in a voltameter given the surface area of the cathode, the desired thickness of the deposit, the density of copper and a constant current. The formula to use is: time = (mass of copper deposited) / (current x electrochemical equivalent of copper) The mass of copper deposited can be calculated as: mass = volume x density = (surface area x thickness) x density The electrochemical equivalent of copper is the amount of copper deposited by one coulomb of charge passing through a copper ion in the electrolyte, and its value is 0.000329 gC^-1. Substituting the given values in the above formulas, we get: mass = (118.8 cm^2 x 10^-6 m) x (9 x 10^3 kgm^-3) = 1.0692 x 10^-3 kg electrochemical equivalent of copper = 0.000329 kgC^-1 time = (1.0692 x 10^-3 kg) / (10 A x 0.000329 kgC^-1) = 3.2548 s Converting the time to minutes, we get: time = 3.2548 s x (1 min / 60 s) = 0.0542 min ≈ 5.4 min Therefore, the answer is 5.4 min.