What is the molecular formula of each of the following compounds? (b) empirical formula NH₂Cl, molar mass = 51.5 g/mol

Key Concepts

Empirical Formula

The empirical formula represents the simplest whole-number ratio of atoms in a compound. For example, the empirical formula NH2Cl indicates that for every one nitrogen atom, there are two hydrogen atoms and one chlorine atom. It does not provide information about the actual number of atoms in a molecule, which can be determined by the molecular formula.

Molecular Formula

The molecular formula gives the actual number of each type of atom in a molecule of a compound. It can be derived from the empirical formula by multiplying the subscripts by a whole number, known as the molecular weight factor. In this case, the molecular formula can be determined by comparing the molar mass of the compound to the molar mass of the empirical formula.

Molar Mass

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 masses of all atoms in the molecular formula. For the compound with an empirical formula of NH2Cl and a given molar mass of 51.5 g/mol, this value is crucial for determining the molecular formula by comparing it to the molar mass of the empirical formula.