A 2.000g sample of magnesium was burned in air to form an oxide. After the product was purified it was found to have a mass of 3.317g. What is the empirical formula for the product?
I know how to find a empirical formula, I just don't understand what masses I am supposed to use. Would it be 2.000g Mg and 1.317g O?
Yes. Mass Mg - 2.000 in the problem.
3.317 - 2.000 = mass oxygen = 1.317 g.
To find the empirical formula for the product, you need to determine the ratio of the elements present in the compound. In this case, you are given the masses of magnesium (Mg) and oxygen (O) in the experiment.
The initial mass of the magnesium sample is 2.000g, and after burning and purifying, the mass of the resulting product is 3.317g. The difference between these two masses (3.317g - 2.000g = 1.317g) represents the mass of oxygen that combined with the magnesium to form the oxide.
Therefore, you are correct in using 2.000g for Mg and 1.317g for O.
To calculate the empirical formula, you need to convert these masses to moles. To do this, divide each mass by their respective molar masses. The molar mass of Mg is approximately 24.31 g/mol, and the molar mass of O is 16.00 g/mol.
For Mg:
2.000g / 24.31 g/mol ≈ 0.0823 mol
For O:
1.317g / 16.00 g/mol ≈ 0.0823 mol
Now you need to determine the simplest whole number ratio of magnesium to oxygen. Divide both moles by the smaller value (in this case, both are the same):
0.0823 mol / 0.0823 mol = 1.000
So, the empirical formula for the product is MgO, meaning the ratio of magnesium to oxygen atoms in the compound is 1:1.