An organic compound contains 78% (by wt.) carbon and remaining percentage of hydrogen. The right option for the empirical formula of this compound is: [Atomic wt. of C is 12, H is 1]

A $CH_2$

B $CH_3$

C $CH_4$

D CH

The answer is B.

Solution

C: $\frac{78}{12} = 6.5$ → 1 ; H: $\frac{22}{1} = 22$ → $\frac{22}{6.5} \approx 3$ Simplest ratio C : H = 1 : 3 Empirical formula = $CH_3$

Concept empirical formula from percentage composition

49 questions from this chapter have appeared across 23 exam years.