A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen (by mass). Calculate the empirical formula.

Question

Quizplus · Accepted Answer

To find the empirical formula, we convert the percentages to grams (assuming 100g of the compound), then to moles, and finally to the simplest whole number ratio. For carbon (C), 40.0g corresponds to 40.0/12.01 = 3.33 moles. For hydrogen (H), 6.7g corresponds to 6.7/1.01 = 6.63 moles. For oxygen (O), 53.3g corresponds to 53.3/16.00 = 3.33 moles. The simplest whole number ratio of C:H:O is 1:2:1, which corresponds to CH2O, matching choice A.

A Compound Contains 40