Kalirren said:Convert everything to moles. Find the ratio of (moles sulphur consumed) to (moles iron consumed). That should give you the atomic ratio of sulphur to iron in the sulphide, which translates easily to a formula.
Percent composition in chemistry refers to the percentage of each element present in a compound by mass. It is calculated by dividing the mass of each element in the compound by the total mass of the compound and then multiplying by 100. This information is helpful in determining the chemical and physical properties of a compound.
To find the percent composition of a compound, first determine the molar mass of the compound by adding the atomic masses of each element present. Then, divide the mass of each element by the total molar mass and multiply by 100. The resulting values represent the percent composition of each element in the compound.
A formula unit is the simplest whole number ratio of ions in an ionic compound. It is similar to a molecule in covalent compounds, but since ionic compounds do not exist as discrete molecules, the term formula unit is used instead.
The empirical formula of a compound can be determined using the percent composition of each element. First, convert the percent composition to grams. Then, divide the grams of each element by its molar mass. Finally, divide the resulting values by the smallest value obtained. The resulting values represent the subscripts in the empirical formula.
The empirical formula represents the simplest whole number ratio of atoms in a compound, while the molecular formula represents the actual number of atoms of each element in a compound. The molecular formula is typically a multiple of the empirical formula. For example, the empirical formula for glucose is CH2O, while the molecular formula is C6H12O6.