Establish the molecular formula of a gaseous compound containing 20% carbon, 26.7% oxygen and sulfur.

| September 23, 2021 | education

Establish the molecular formula of a gaseous compound containing 20% carbon, 26.7% oxygen and sulfur. It is known that the relative density of this compound with respect to nitrogen is 2.143

Let’s determine the mass content of sulfur:

w (S) = 100 – w (C) – w (O) = 100 – 20 – 26.7 = 53.3 (%).

Mass ratio of elements in the compound:

w (C): w (O): w (S) = 20: 26.7: 53.3

Taking into account the atomic weights, let’s move on to the quantitative ratio:

n (C): n (O): n (S) = w (C) / M (C): w (O) / M (O): w (S) / M (S) =

= 20/12: 26.7 / 16: 53.3 / 32 = 1.67: 1.67: 1.67 = 1: 1: 1.

Thus, in this compound, there is 1 O atom and 1 S atom per 1 C atom, therefore the formula of this compound can be written as CnOnSn.

Determine the molecular weight of the compound:

M (CnOnSn) = DN2 (CnOnSn) * M (N2) = 2.143 * 28 = 60 (amu).

Let’s compose and solve the equation:

12 * n + 16 * n + 32 * n = 60, whence n = 1 and the compound formula: COS (carbonyl sulfide).



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.