Question

Molecular weight of an alkane was found to be 142.suggest its molecular formula.

Answer 1

General molecular formula for alkanes is C(n)H(2n+2) where n is no. of carbon atoms.

12 is mass of carbon and 1 is of hydrogen.

Total given mass is 142.

12n +1(2n+2) = 142.

14n +2 = 142

14n = 140

n= 10

C₁₀H₂₂