Students use the mole concept to calculate various concentrations of chemical solutions. Students determining the concentrations of  four unknown solutions of sodium hydrochloric acid of unknown concentration by titrating these solutions with known concentrations of sodium hydroxide. The activity sheets included focus the students attention to problems involving conversion of grams to moles, moles to grams, and calculating morality. The laboratory unit provided in this kit includes a term sheet, activity sheets, two laboratory exercises, a crossword puzzle, a test, an answer key, and a balance sheet.