# Number of electron for complete Discharge [closed]

What is the answer for question 17 and what is mean by "number of electrons for complete discharge?"

Which of the following needs the largest number of electrons for complete discharge during an electrolysis process?
a) 3 mol of $$\ce{Al^{3+}}$$
b) 4 mol of $$\ce{Al^{3+}}$$ ions
c) 5 mol of $$\ce{OH^-}$$ ions
d) 7 mol of $$\ce{O^{2-}}$$ ions

## closed as off-topic by airhuff, Tyberius, Ivan Neretin, orthocresol♦Oct 4 '18 at 11:00

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## 1 Answer

$$\text{a)} 3\times+3 = 9$$ $$\text{b)} 4\times+3 = 12$$ $$\text{c)} 5\times-1= -5$$ $$\text{d)} 7\times-2 = -14$$ This seems like an ambiguous question.

• b) "needs" the most electrons supplied to become neutral
• d) "gives up" more electrons than b) to become neutral.

I'd have to take "needs" literally and go with b) as the answer.