A compound contains 40% C, 6.67% H and 53.33% O by mass. Its empirical formula is (C = 12, H = 1, O = 16)

Answer: D

Moles in 100 g: C = 3.33, H = 6.67, O = 3.33. Dividing by the smallest (3.33) gives C : H : O = 1 : 2 : 1. Empirical formula is CH2O.

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