Bright Tutorials Bright Tutorials
ICSE Class 10 Chemistry Question 12 of 23

Solved Sample Paper 3 — Question 6

Back to all questions
6
Question

Question 4(ii)

An organic compound has an empirical formula (CH2O). Its vapour density is 45. Then what will be the molecular formula of the compound?

Answer

Given,

Empirical formula = CH2O

Hence, empirical formula mass = 12 + 2(1) + 16 = 12 + 2 + 16 = 30 g

Molecular weight = 2 x Vapour density = 2 x 45 = 90

Molecular formula = n x empirical formula

where,

n = molecular massempirical formula mass\dfrac{\text{molecular mass}}{\text{empirical formula mass}}

∴ n = 9030\dfrac{90}{30} = 3

Hence, molecular formula = 3 x CH2O = C3H6O3

Therefore, the molecular formula of the compound is C3H6O3