TeXes Science Practice Test

How many Faradays are required to reduce one mole of Ni+2 to Ni(s)?

1. One Faraday

2. Two Faradays

3. Three Faradays

4. Four Faradays

The correct answer is: Two Faradays

To determine how many Faradays are required to reduce one mole of nickel ions (Ni²⁺) to solid nickel (Ni), it is essential to understand the process of reduction in electrochemistry. During this reduction, each Ni²⁺ ion needs to gain two electrons to become neutral nickel metal. According to Faraday's laws of electrolysis, one Faraday corresponds to the charge of one mole of electrons, which is approximately 96,485 coulombs. Since one mole of Ni²⁺ requires two moles of electrons for its reduction, this means that two Faradays are necessary to provide the equivalent charge to reduce one mole of Ni²⁺ to Ni(s). This relationship highlights the stoichiometric conversion of ion charge to moles of electrons, leading to the conclusion that reducing one mole of Ni²⁺ ions indeed requires two Faradays of electric charge.