Question

interactive example molecular formula questions what is the molecular formula for vinegar? vinegar contains carbon, hydrogen, and oxygen with percent masses of 40.01% c, 6.70% h, and 53.29% o, respectively. determine the molecular formula of the compound, with a molar mass of 60.052 g/mol. molecular formula =

Explanation:

Step1: Assume 100g of the compound

We assume we have 100g of the compound, so the masses of each element are: C = 40.01g, H = 6.70g, O = 53.29g.

Step2: Calculate moles of each element

Moles of C: $\frac{40.01\mathrm{g}}{12.01\mathrm{g/mol}} \approx 3.332\mathrm{mol}$
Moles of H: $\frac{6.70\mathrm{g}}{1.008\mathrm{g/mol}} \approx 6.647\mathrm{mol}$
Moles of O: $\frac{53.29\mathrm{g}}{16.00\mathrm{g/mol}} \approx 3.331\mathrm{mol}$

Step3: Find the empirical formula

Divide each mole value by the smallest mole value (≈3.331) to get the ratio:
C: $\frac{3.332}{3.331} \approx 1$
H: $\frac{6.647}{3.331} \approx 2$
O: $\frac{3.331}{3.331} = 1$
So the empirical formula is $\mathrm{CH_2O}$.

Step4: Calculate empirical formula mass

Empirical formula mass: $12.01 + 2(1.008) + 16.00 = 30.026\mathrm{g/mol}$

Step5: Determine the molecular formula multiplier

Molecular mass is 60.052 g/mol (given). Multiplier $n = \frac{60.052}{30.026} = 2$

Step6: Find the molecular formula

Multiply the empirical formula by $n$: $(\mathrm{CH_2O})_2 = \mathrm{C_2H_4O_2}$

Answer:

$\mathrm{C_2H_4O_2}$