Some Basic Principles Of Organic Chemistry Question 77
Question: An organic compound contains C, H and O in the proportion of 6 : 1 : 8 by weight, respectively. Its vapour density is 30. Its molecular formula will be
Options:
A) $ C_2H_4O_2 $
B) $ CH_4O $
C) $ CH_2O $
D) $ C_3HO $
Show Answer
Answer:
Correct Answer: A
Solution:
| Elements | No.of moles | Simple ratio |
|---|---|---|
| C | 6 6/12 = 0.5 = 1 | 1 |
| H | 1 1/1 = 1 = 2 | 2 |
| O | 8 8/16 = 0.5 = 1 | 1 |
Thus, Empirical formula = $ \underset{\text{(enol form)}}{\mathop{C_6H_5-\underset{O}{\mathop{\underset{||}{\mathop{C}},}},-CH=\underset{OH}{\mathop{\underset{|}{\mathop{C,}},}},-CH_3}}, $ Empirical formula mass = 30 Mol.
mass = 2 × V.D.
= 2 × 30 = 60 $ n=\frac{60}{30}=2 $
Mol. formula = $ {{(CH_2O)}_2}=C_2H_4O_2 $ .
