How do you calculate how much of a substance is deposited during an electrolytic process?

Question

please answer as soon as possible

10 points to the best answer

Answer 1

1. Write the half-reactions occurring at the cathode and the anode.

2. Write the balanced reaction, and note (from the half-reactions) how many moles of electrons are transferred per mole of reaction.

3. Calculate the total number of coulombs of charge that were passed through the solution, by multiplying current by time. Convert this into moles of electrons (faradays).

4. Use this value along with the one obtained in 2) to determine how many moles of reaction occurred.

5. Use the stoichometry of the reaction to determine how many moles of product were formed in total.

6. Multiply by the molar mass to obtain an answer in terms of mass.

Answer 2

1 mole of electrons is passed by 96500 coulombs of electricity.

Number of coulombs = current (in amperes) X time (in seconds)

Look at electrode equation to work out how many moles of electrons are needed to produce 1 mole of product.

e.g.

Na+ + e --> Na 1 mole of electrons --> one mole of sodium.

BUT

Mg2+ + 2e --> Mg 2 moles of electrons --> one mole of magnesium.

Convert moles to mass in the usual manner.