Question

If a constant current of 1.50 × 10⁸ A is passed through a molten mixture of aluminum oxide and cryolite for 4.00 hour ________ kg of aluminum can be produced.

Answer 1

To determine the mass of aluminum produced by electrolysis, calculate the total charge, apply Faraday's Law, use the mole ratio from the chemical equation and convert moles of aluminum to mass.

Step-by-step explanation:

The question is asking how much aluminum can be produced by passing a current of 1.50 × 10⁸ A through a molten mixture of aluminum oxide and cryolite for 4.00 hours.

To find the mass of aluminum produced, you need to follow these steps:

1. Calculate the total charge (Q) passed in coulombs using Q = current (I) × time (t), where time is in seconds.
2. Use Faraday's Law of Electrolysis which states that the amount of substance produced at an electrode during electrolysis is proportional to the amount of electricity that is passed through the electrolyte. The charge (Q) is related to the amount (n) of aluminum through the equation Q = n × F, where n is the number of moles of electrons and F is Faraday's constant (96485 C/mol).
3. From the balanced chemical equation, you can see that 4 moles of Al are produced per 12 moles of electrons. Therefore, calculate the moles of Al produced using the mole ratio from the balanced equation.
4. Convert the moles of Al to mass using the molar mass of Al (26.98 g/mol).

Remember to convert the time from hours to seconds and the mass to kilograms as necessary.