Speedy's Chemistry 3/4 Questions

[Yacoubb]

1. Why is D incorrect here?
If you find the half-equations and balance them as if you were to construct an overall redox equation, you would find that once balanced, the number of hydrogen ions produced in oxidation of methanol is equal to the amount of hydrogen ions consumed at the cathode in the reduction of oxygen gas. The correct answer is C; in reality, the efficiency is not 100% due to chemical energy being converted to other forms of energy, such as heat energy.

2. Why must it be more than 2.1 V?
During recharge, we always provide a voltage to the electrolytic cell of a voltage more than the potential difference because of resistance in the connecting wires of the circuit, which would mean that less than 2.1V actually reaches the solution to be used in electrolysis, and so you wouldn't be able to induce the non-spontaneous reaction.

Hope this helps

[speedy]

1. Why is D incorrect here?
If you find the half-equations and balance them as if you were to construct an overall redox equation, you would find that once balanced, the number of hydrogen ions produced in oxidation of methanol is equal to the amount of hydrogen ions consumed at the cathode in the reduction of oxygen gas. The correct answer is C; in reality, the efficiency is not 100% due to chemical energy being converted to other forms of energy, such as heat energy.

2. Why must it be more than 2.1 V?
During recharge, we always provide a voltage to the electrolytic cell of a voltage more than the potential difference because of resistance in the connecting wires of the circuit, which would mean that less than 2.1V actually reaches the solution to be used in electrolysis, and so you wouldn't be able to induce the non-spontaneous reaction.

Hope this helps

Ahh brilliant, thank you