Alkane has a relative density in air of 2. The average molecular weight of air is 29. Derive the alkane formula

univerkov | August 5, 2021 | education

Let the formula for an unknown alkane be CnH2n + 2.

Let’s find the molecular weight of the unknown alkane:

M (CnH2n + 2) = M (air) * Dair (CnH2n + 2) = 29 * 2 = 58 (amu).

Let’s compose and solve the equation:

12 * n + 1 * (2n + 2) = 58,

n = 4, whence the molecular formula of the alkane: C4H10 (which corresponds to butane or isobutane).

Answer: C4H10.

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.