Find the molecular formula for a hydrocarbon containing

Find the molecular formula for a hydrocarbon containing 87.8% carbon and 12.2% hydrogen. The relative density of this substance for hydrogen is 41.

Let’s implement the solution:

According to the condition of the problem, we will write the data:
W (C) = 87.8%

W (H) = 12.2%

D (H2) = 41

CxHy -?

Calculations:
M (CxHy) = D (H2) * M (H2) = 41 * 2 = 82 g / mol.

Let’s determine the amount of hydrogen, carbon based on the values of the mass fraction of the substance:
Y (C) = 87.8 / 12 = 7.3 mol;

Y (H) = 12.2 / 12 = 1 mol.

Ratio:

C: H = X: Y = 7.3: 1 = 7: 1

The simplest formula: С7Н shows that the hydrocarbon is classified as unsaturated.

Let’s set the formula:
СnH2n – 2 = 82 g / mol;

CnH2n = 80;

n = 5 7 = 6

C6H10 – hexine.

M (C6H10) = 12 * 6 +10 = 82 g / mol.

Answer: the hydrocarbon formula is C6H10 (hexine).