Question

Methyl butyrate is a compound that is partially responsible for the flavor of apples. It consists of 58.80% C, 9.87% H, and 31.33% O. What is the empirical formula of methyl butyrate? Explain.

Answer 1

Assume you have 100g of the sample, in which

mass of C = 58.80g

mass of H = 9.87g

mass of O = 31.33g

Now calculate the number of moles of the above species

Number of moles = Mass given / Molecular mass

No. of moles (C) = 58.80 / 12.01 = 4.90

No. of moles (H) = 9.87 / 1.008 = 9.79

No. of moles (O) = 31.33 / 16.0 = 1.95

Now, Divide each mole value by the smallest number of moles calculated.

4.90 / 1.95 =2.5

9.79 / 1.95 = 5.0

1.95 / 1.95 = 1

Now, Round to the nearest whole number. (Multiply by 2)

moles of C = 5

Moles of H = 10

moles of O = 2

Therefore empirical formula comes out to be C₅H₁₀O₂.