Answer:
Cr2O3
Explanation:
To find the empirical formula, which is the smallest whole number ratio of a compound, the following is done:
68.4% Cr = 68.4g of Chromium
31.6% O = 31.6g of Oxygen
Since, Cr = 52, O = 16, divide each mass by their respective atomic mass to convert to moles.
Cr = 68.4/52 = 1.315 mol
O = 31.6/16 = 1.975 mol
- Next, we divide each mole value by the smallest value (1.315mol)
Cr = 1.315/1.315 = 1
O = 1.975/1.315 = 1.50
The ratio or Cr to O is 1:1.5
We multiply this ratio by 2 to get the whole number ratio as follows:
2 × 1: 2 × 1.5
2:3
Hence, the empirical formula of Cr and oxygen is Cr2O3.
