Question

Although coal is a complex mixture of substances, its elemental composition can be approximated by the formula C135H96O9NS. Using this chemical formula, calculate the percentage, by mass, of carbon (C) in coal.

Answer 1

Answer:

85%

Explanation:

Firstly, we will need to calculate the molar mass of the molecule. We simply use the atomic masses of each of the elements. The atomic masses are as follows:

C = 12

H = 1

O = 16

N = 14

S = 1

All units are in a.m.u

The molecular mass is thus:

(135 × 12) + (96 × 1) + (16 × 9) + 14 + 32 = 1906g/mol

The percentage by mass of carbon = (135 × 12)/1906 × 100% = 85%