The hydrocarbon contains 88.89% carbon. Its air density is 1.862.

The hydrocarbon contains 88.89% carbon. Its air density is 1.862. Find the molecular formula of this carbon, write the formulas and names of its possible isomers

Let’s implement the solution:
1. Let’s calculate the molar mass of the substance – CxHy according to the formula:
M (air) = 29 g / mol;
M (CxHy) = M (air) * D (air) = 29 * 1.862 = 53.998 g / mol.
2. Determine the amount of moles of carbon, hydrogen:
Y (C) = m / M = 88.89 / 12 = 7.4 mol;
m (H) = 100 – 88.89 = 11.11 g;
Y (H) = 11.11 / 1 = 11.11 mol.
3. Let us establish the simplest formula of the substance:
C: H = X: Y = 7.4: 11.11 = 1: 1.5 = 1: 2 (data obtained by dividing by the smallest number 7.4).
4. The simplest formula is CH2, so. Corresponds to the general formula – СnH2n – 2
5. Let’s make the calculations:
12n + 2 = 53.998;
12n = 51.998;
n = 4.5, FROM HERE WE DETECT THE MOLECULAR FORMULA: С4Н6 – butadiene, M (C4H6) = 54 g / mol.
6. Let’s compose the formulas of the isomers:
H2C = CH – CH = CH2 – butadiene – 1.3;
Н3С – СН = С = СН2 – butadiene – 2,3
Answer: C4H6 – butadiene.