Set the molecular formula and indicate the hydrocarbon class according

Set the molecular formula and indicate the hydrocarbon class according to the following data Mr = 84, W (c) = 0.857, w (H) = 0.143

1. Let’s imagine that the fractions are the masses of the corresponding elements:

m (C) = 0.857 and m (H) = 0.143;

2.determine their chemical quantities:

n (C) = 0.857: 12 = 0.0714 mol;

n (H) = 0.143: 1 = 0.143 mol;

3. Establish the empirical formula of the hydrocarbon from the ratio of the quantities found:

n (C): n (H) = 0.0714: 0.143;

n (C): n (H) = 1: 2, we got that the simplest or empirical formula of this substance has the form: CH2;

4. Let us find how many times the relative mass of the hydrocarbon is greater than the molecular mass of the simplest formula:

Mr (CH2) = 12 + 2 = 14;

Mr (HC): Mr (CH2) = 84: 14 = 6;

5. Let us find the molecular formula by multiplying the number of each element in the hydrocarbon by 6 to obtain the hexene formula C6H12.

Answer: C6H12.