Be able to convert from molecules to number of atoms in molecules. Chemical Equations Be able to write balance equations and to write equations from sentences. Average atomic mass is the weighted average of the isotopes. Formula Weight is the sum of the atomic weights of the atoms in the formula. Empirical Formulas Empirical formula is the lowest whole number ratio of moles in a formula.
Molecular formula is the actual ratio of elements in the molecule.
The ratio of the MW to Empirical Formula Weight is a whole number. The stoichiometric ratio is the ratio of the moles of unknown to moles of known. Be able to work Limiting Reagent problems. Molarity Molarity is the moles of solute per liter of solution. DO NOT form ions.