Determine the empirical formulas of the compounds with the following compositions by mass: 24.5% Na, 14.9% Si, and 60.6% F
Each percentage represents the number of grams of an element per 100.0 grams of that compound. Convert these masses to moles using molar masses.
To find the empirical formula of the compound that has 24.5% Na, 14.9% Si, and 60.6% F. We must:
- Assume there is 100.0 g of compound to get the number of grams per element. Therefore:
Na = 24.5 g Si = 14.9 g F= 60.6 g
The % by mass of Nа is 24.5%, Si is 14.9 %, and of F is 60.6 %.
Let us assume that the mass of the compound is 100 grams, hence
The mass of Na is
The mass of Si is
The mass of F is
Let us find the empirical formula of a given compound.
First, we have to find the number of moles of Na, Si, and F.
To find the empirical formula, we have to divide each number of moles by the smallest one.
Therefore, the empirical formula is