Question

what is the formula of the ionic compound between fe³⁺ and o²⁻?
fe₆o₆
feo
2fe3o
fe₂o₃

Explanation:

Step1: Determine charge - balance

For an ionic compound to be neutral, the total positive charge must equal the total negative charge. The charge on $Fe^{3 +}$ is $+ 3$ and on $O^{2-}$ is $-2$.

Step2: Find the least - common multiple

The least - common multiple of 3 and 2 is 6.

Step3: Calculate the number of ions

To get a total charge of 6 for both positive and negative, we need 2 $Fe^{3+}$ ions ($2\times3 = 6$) and 3 $O^{2 -}$ ions ($3\times2=6$).

Answer:

$Fe_{2}O_{3}$