Question

What is the ratio of Fe3+ ions to O2- ions in a neutral compound?

1:2
2:1
2:3
3:2,

Answer 1

The answer is 2:3. Because the lowest common denominator of 2 and 3 is 6, we find that for every 2 Fe3+ ions, we would need 3 O2- ions to neutralize the charge. The other answers do not fit this idea, as the math doesn't then add up to come to a neutral charge.