What is the molecular formula of the following compound? Empirical formula C3H6O2 (M=74.08 g/mol)
3*C + 6*H + 2*O = ??
Look up atomic masses on the periodic table.
To determine the molecular formula of a compound using the empirical formula and the molar mass, we need to find the factor by which the empirical formula mass needs to be multiplied to obtain the molar mass.
The empirical formula mass of C3H6O2 can be calculated as follows:
(3 mol of C atoms × 12.01 g/mol) + (6 mol of H atoms × 1.01 g/mol) + (2 mol of O atoms × 16.00 g/mol) = 42.08 g/mol.
To find the factor, divide the molar mass of the compound (74.08 g/mol) by the empirical formula mass (42.08 g/mol):
74.08 g/mol ÷ 42.08 g/mol = 1.76.
This tells us that the molecular formula must be multiplied by 1.76 to obtain the molar mass.
Therefore, multiplying the empirical formula by 1.76, we get the molecular formula:
C3H6O2 × 1.76 = C5H10O3.
The molecular formula of the compound is C5H10O3.
To find the molecular formula of a compound given its empirical formula and molar mass, you need to determine the factor by which the empirical formula must be multiplied to obtain the molar mass.
In this case, the empirical formula is C3H6O2, and the molar mass is 74.08 g/mol. Let's calculate the empirical formula's molar mass:
- Carbon (C) has an atomic mass of 12.01 g/mol.
- Hydrogen (H) has an atomic mass of 1.01 g/mol.
- Oxygen (O) has an atomic mass of 16.00 g/mol.
Calculating the molar mass of C3H6O2:
(3 * 12.01 g/mol) + (6 * 1.01 g/mol) + (2 * 16.00 g/mol) = 74.09 g/mol
The molar mass calculated for the empirical formula is close to the given molar mass, 74.08 g/mol. This indicates that the empirical formula is already the molecular formula.
Therefore, the molecular formula of the compound is C3H6O2.