Calculating empirical formula o Convert percentages to grams Assume you start with 100g of compound o Convert grams to moles o Write pseudoformula using moles as subscripts o Divide all by smallest number of moles If result is within 1 of whole number round to whole number o Multiply all mole ratios by number to make all whole numbers If ratio 5 multiply all by 2 if ratio 33 or 67 multiply all by 3 if ratio 25 or 75 multiply all by 4 etc o Skip if already whole numbers Chemical reactions o Involve the rearrangement of atoms to form new molecules o Remember in a chemical reaction matter is neither created nor destroyed o The nature of the elements don t change Elements in elements out Chemical equations o Chemical formula of each molecule involved o Ratio of molecule involves o State of molecule gas liquid etc Aq aqueous dissolved in water Ch 3 hw due 1159 Sunday night Stoichiometry o Part of chemistry that deals with the quantities of chemicals in a reaction o
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