Question

Ethanedioic acid, a compound that is present in many vegetables, has a molar mass of 90.04 g/mol and a composition of 26.7% Carbon, 2.2% Hydrogen, and 71.1% oxygen. Calculate the empirical formula and determine the compound formula.

Answer 1

Empirical CHO2

Molecular C2H2O4

Step-by-step explanation:

To determine the formulas, firstly, we need to divide the percentage compositions by the atomic masses.

Kindly note that the atomic mass of carbon, oxygen and hydrogen are 12, 16 and 1 respectively. We proceed with the division as follows:

C = 26.7/12 = 2.225

H = 2.2/1 = 2.2

O = 71.1/16 = 4.44375

We then proceed to divide by the smallest value which is 2.2 in this case

C = 2.25/2.2 = 1

H = 2.2/2.2 = 1

O = 4.44375/2.2 = 2

Thus, the empirical formula is CHO2

We now proceed to get the molecular formula as follows

[12+ 1 + 16(2) ]n = 90.04

45n = 90.04

n = 90.04/45 = 2

The molecular formula is :

C2H2O4