Analysis of a compound containing only C and Cl revealed that it contains 33.33 % C atoms by number and has a molar mass of 248.75 g/mol. What is the molecular formula of this compound?

Empirical formula of a compound is it's simplest formula while the molecular formula gives the exact number of moles of atoms of the component elements in one mole of the compound.

To calculate the molecular formula;

Step 1:

Write the elements in the compound with their percentage quantities.

Carbon = 33.33%

Chlorine = 100 - 33.33 = 66.67%

Step 2:

Divide both components by its relative atomic mass

C = 12, Cl = 35.5

Carbon 33.33/ 12 = 2.7775

Chlorine 66.67/ 35.5 =1.8780

Step 3: divide both values by the smallest

1.8780 is the smallest

So therefore,

2.7775/ 1.8780 = 1.4790 = ~2

1.8780/ 1.8780 = 1

Empirical formulae = C2Cl

(C2Cl)x = 248.75

(12*2 + 35.5)x = 248.75

(59.5)x = 248.75

x = 248.75 / 59.5

x = 4.18 = 4

Molecular formula = C8Cl4