Answer:
AlN₃O₉
Explanation:
Assume that you have 100 g of the compound.
Then you have 12.7 g Al, 19.7 g N, and 67.6 g O.
1. Calculate the moles of each atom
Moles of Al = 12.7 × 1/26.98 = 0.4707 mol Al
Moles of N = 19.7 × 1/14.01 = 1.406 mol N
Moles of O = 67.6 × 1/16.00 = 4.225 mol O
2. Calculate the molar ratios.
Al: 0.4707/0.4707 = 1
N: 1.406/0.4707 = 2.987
O: 4.225/0.4707 = 8.976
3. Determine the empirical formula
Round off all numbers to the closest integer.
Al: 1
N: 3
O: 9
The empirical formula is AlN₃O₉.
