Determine the empirical formula of each of the following compounds if a sample contains (c) 89.14% Au and 10.86% O by mass.

Key Concepts

Empirical Formula

The empirical formula of a compound represents the simplest whole-number ratio of the elements present in that compound. It is derived from the percentage composition of each element, allowing chemists to understand the basic composition without detailing the molecular structure.

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is crucial for converting the mass percentages of elements into moles, which are then used to determine the empirical formula by finding the simplest ratio of the elements.

Conversion from Mass Percent to Moles

To find the empirical formula, the mass percent of each element must be converted to moles. This is done by dividing the mass of each element by its molar mass. The resulting values are then simplified to the smallest whole-number ratio, which gives the empirical formula.