(b) If the molecular weight is 326.26, what is the molecular formula?

Verified step by step guidance

1. Step 1: The first step in determining the molecular formula is to calculate the empirical formula weight. This is done by adding up the atomic weights of all the atoms in the empirical formula.
2. Step 2: Once you have the empirical formula weight, divide the molecular weight by the empirical formula weight. This will give you a ratio, which should be a whole number or very close to a whole number.
3. Step 3: If the ratio is not a whole number, round it to the nearest whole number. This is because the molecular formula must contain whole numbers of atoms.
4. Step 4: Multiply each subscript in the empirical formula by the ratio you calculated in step 2. This will give you the molecular formula.
5. Step 5: Check your work by calculating the molecular weight of the molecular formula you determined. It should match the given molecular weight.

Key Concepts

Molecular Weight

Molecular weight, or molar mass, is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic weights of all atoms in a molecule, which can be found on the periodic table. Understanding molecular weight is crucial for determining the composition and stoichiometry of chemical compounds.

Empirical Formula

The empirical formula represents the simplest whole-number ratio of the elements in a compound. It provides insight into the relative proportions of each element but does not convey the actual number of atoms in a molecule. To derive the molecular formula from the empirical formula, one must know the molecular weight of the compound.

Molecular Formula

The molecular formula indicates the actual number of each type of atom in a molecule of a compound. It is derived from the empirical formula by multiplying the subscripts by a whole number, which is determined by dividing the molecular weight by the empirical formula weight. This formula is essential for understanding the structure and reactivity of the compound.