Question

Complete combustion of 0.858 g of compound X gives 2.63 g of CO₂ and 1.28 g of H₂O. The lowest molecular weight X can have is 

(a) 172

(b) 129

(c) 86

(d) 43

Answer 1

Correct option is (d) 43

Percentage of C = \(\frac{12}{44} \times \frac{2.63}{0.858} \times 100 = 83.59\)

Percentage of H = \(\frac{2}{18} \times \frac{1.28}{0.858}\times 100 = 16.57\)

Empirical formula of X = C₃H₇

Empirical formula wt. of X = 36 + 7 = 43