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Question
The compound A has the following percentage composition by mass: C =26.7%, O = 71.1%, H = 2.2%.
Determine the empirical formula of A.(Answer to one decimal place) (H=1,C=12,O=16)
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Solution
| Element | Atomic mass | Percentage | Relative number of moles | Simplest mole ratio | Whole number ratio |
| C | 12 | 26.7 | 26.7/12 = 2.2 | 2.2/2.2 = 1 | 1 |
| O | 16 | 71.1 | 71.1/16 = 4.44 | 4.44/2.2 =2 | 2 |
| H | 1 | 2.2 | 2.2/1 = 2.2 |
2.2/2.2 = 1 | 1 |
So the empirical formula of the compound is CO2H.
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