Take a 100 g sample to give you
65.5 g C atoms
5.5 g H atoms
29.0 g O atoms
Convert each to mols. mols = grams/molar mass
C = 65.5/12 = estimated 5.5
H = 5.5/1 = 5.5
O = 29.0/16 = about 1.8
Now find the ratio of the elements to one another with the smallest whole number being 1.00 The easy way to do that is to divide all the numbers by the smallest number. The smallest number is 1.8
So C is 5.5/1.8 = 3.05; round to 3.0
H is 5.5/1.8 = 3.05; round to 3.0
O is 1.8/1.8 = 1.00 = 1.0
empirical formula is C3H3O and the empirical mass is 3*12 + 3*1 + 16 = about 55
mols mass is 110.
empirical formula x ?whole number = 110
?whole number = 110/55 = 2 so tahe molecular formula is (C3H3O)2 or C6H6O2 with a molar mass of 72 + 6 + 32 = 110
What is the empirical formula of a molecule containing 65.5% carbon, 5.5% hydrogen, and 29.0% oxygen?
-I found this to be C3H3O and WebAssign says it's right. I need help with part b.
If the molar mass of the above compound is 110 grams/mole, what is the molecular formula?
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1 answer