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Welcome to Chemistry!!. M & M Question. You and your partner will be given a cup of M&M’s. It is your job to find the mass percent of each color in your cup. Do not put the M&M’s on the lab table if you intend to eat them!. M & M Question.
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M & M Question • You and your partner will be given a cup of M&M’s. It is your job to find the mass percent of each color in your cup. Do not put the M&M’s on the lab table if you intend to eat them!
M & M Question • We can use this same technique to find the mass percent in different compounds.
Percent Composition • We can use the information from the formula of compound to find the percent composition • We use the mass of each element in 1 mole of the compound
Percent Composition • For example, we are going to use the compound ethanol with the formula C2H5OH • First find the molecular weight of ethanol
Percent Composition • Mass of C = 12.01 x 2 = 24.02 • Mass of H = 1.008 x 6 = 6.048 • Mass of O = 16.00 x 1 = 16.00 • Sum = 46.07g = molecular mass
Percent Composition • Solve for mass percent of each element • MP of C = 24.02/46.07 x 100% • MP of C = 52.14%
Percent Composition • MP of H = 6.048/46.07 x 100% • MP of H = 13.13% • MP of O = 16.00/46.07 x 100% • MP of O = 34.73%
Percent Composition • The easiest way to check is to make sure that all your percents total 100%!!!