1: How is the empirical formula used to determine percent composition? 2: Analyze the role coefficients of chemical reactions play in stoichiometry

Answer 1

Percent composition is usually used to find the empirical formula. You divide the percentage of each atom by its' molar mass and calculate the number of moles of each atom. You then divide by the smallest number of moles and construct the empirical formula from the resulting ratio.

The coefficients in a reaction tell you the molar ratios of each compound to each other.