WAEC - Chemistry (2018 - No. 9)
An organic compound has the empirical formula \(CH_{2}\). If its molar mass is 42\(gmol^{-1}\), what is its molecular formula? (C = 12.0, H = 1.0)
\(C_{2}H_{4}\)
\(C_{3}H_{4}\)
\(C_{3}H_{6}\)
\(C_{4}H_{8}\)
Explication
Given the molecular formula, \(CH_{2}\).
The empirical formula will be \((CH_{2})n\)= 42
\((12+(2\times1))n =42\)
⇒ \(14n =42\)
n = 3, hence the empirical formula is \(C_{3}H_{6}\)