Question

A 3.192-gram sample of magnesium sulfate was heated in a beaker. 10 minutes after heating was completed, the mass of the sample was 1.559g. No chemical reaction occurred. What is the molecular formula for the sample of magnesium sulfate that was heated? Show all work.

The empirical formula of a compound is C3H2O. If the molar mass of the compound is found to be 216 g/mol, find the molecular formula (true formula). You must show all work with the units.

Determine the empirical formula of the following compound if a sample contains 55.80% carbon, 7.038% hydrogen, and 37.17% oxygen by mass. You must show all work with the units.

Answer 1

The molecular formula is (C3H2O) * 2.9189 ≈ C9H6O3. the molecular formula, you need to know the molar mass of the empirical formula and the molar mass of the molecular formula. Divide the molar mass of the molecular formula by the molar mass of the empirical formula to get the ratio of the molar masses.

Step-by-step explanation:

To determine the molecular formula of a compound, you first need to find the empirical formula. In this case, we are given that the empirical formula is C3H2O and the molar mass is 216 g/mol. To find the empirical formula, you need to determine the ratio of the number of atoms of each element in the compound. For carbon, there are three atoms, for hydrogen there are two atoms, and for oxygen, there is one atom. So the empirical formula is C3H2O.

To find the molecular formula, you need to know the molar mass of the empirical formula and the molar mass of the molecular formula. Divide the molar mass of the molecular formula by the molar mass of the empirical formula to get the ratio of the molar masses. Multiply the subscripts in the empirical formula by this ratio to get the subscripts in the molecular formula. In this case, the ratio of the molar masses is 216 g/mol / 74 g/mol = 2.9189. So the molecular formula is (C3H2O) * 2.9189 ≈ C9H6O3.