Answers and Explanations
REVIEW QUESTIONS
1 . D
Avogadro’s number (6.022 × 10^23 ) defines the number of particles present in 1 mole of
anything. So there are 6.022 × 10^23 electrons in 1 mole of electrons.
2 . B
The reduction of one mole of Ni2+ to 1 mole of Ni (s) requires 2 moles of electrons. The transfer
of 1 mole of electrons is equivalent to the transfer of 1 F of charge. Therefore, since 2 moles of
electrons are required to reduce 1 mole of Ni2+, 2 F are required.
3 . B
In order to solve this problem, first determine the number of moles of Au present in 0.600 g.
Next, determine the number of moles of electrons used to reduce Au3+ (aq) to 0.00300 mol of
Au (s). From the given reduction half-reaction of Au, it is evident that for every mole of Au3+, 3
moles of electrons are transferred in order to produce 1 mole of Au (s); therefore,
Finally, convert 0.00900 mol e− to its equivalent in C: