Question

In an experiment, the molar mass of the compound with empirical formula C2H3O2 was determined to be 118.084 g/mol. What is the molecular formula of the compound?For both questions, show your work or explain how you determined the formulas by giving specific values used in calculations

Answer 1

C₄H₆O₄

Step-by-step explanation

Given:

The empirical formula of the compound is C₂H₃O₂

The molecular mass of the compound = 118.054 g/mol

To get the molecular formula of the compound, you need to know the actual number of atoms of each element by equating the empirical formula to the molecular mass as follows:

From the Periodic Table:

Molar mass of H = 1.00784 g/mol

Molar mass of O = 15.999 g/mol

Molar mass of C = 12.0107 g/mol

`\begin{gathered} (C_2H_3O_2)_n=118.054 \\ (2C+3H+2O)_n=118.054 \\ (2*1\text{2}.0107+3*1.00784+2*\text{15}.999)_n=118.054 \\ (24.0214+3.02352+31.998)_n=118.054 \\ (59.04292)_n=118.054 \\ \text{Divide both sides by 59.04292} \\ \frac{(59.04292)_n}{59.04292_{}}=(118.054)/(59.04292) \\ n=1.9995 \\ n\approx2 \end{gathered}`

Hence, the molecular formula of the compound is:

`(C_(2)H_(3)O_(2))_2=C_4H_6O_4`