Answer
The empirical formula for the compound is Al₂O₃
Step-by-step explanation
Given:
Grams of Al = 1.99 g
Grams of O = 1.76 g
What to find:
The empirical formula for the compound.
Step-by-step solution:
The first step is to convert the number of grams of each element into moles as shown below using the molar masses of O = 15.999 g/mol and Al = 26.9815 g/mol.
Note: Mole = Mass/Molar mass
Moles Al = 1.99g/26.9815 g/mol = 0.074 mol
Moles O = 1.76g/15.999 g/mol = 0.11
The next step is to divide the number of moles of each element by the smallest number obtained:
Al = 0.074/0.074 = 1
O = 0.11/0.074 = 1.5
The final step is to multiply the mole ratio by 2 to get the simplest whole number ratio:
Al = 1 x 2 = 2
O = 1.5 x 2 = 3
Hence, the empirical formula for the compound is Al₂O₃