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Empirical and molecular formula, percentage composition
JEE Main level
Single correct option
Difficulty 2 of 3
mc026
A hydrocarbon contains
82.76%
carbon by mass and has a vapour density of
29
(C = 12, H = 1). Its molecular formula is:
A
C
X
2
H
X
5
B
C
X
3
H
X
8
C
C
X
5
H
X
12
D
C
X
4
H
X
10
Answer: D
C : H
=
6.90
:
17.24
=
1
:
2.50
, i.e.
2
:
5
, empirical formula
C
X
2
H
X
5
(mass 29). Molar mass
=
2
×
29
=
58
, so
n
=
58/29
=
2
and the formula is
C
X
4
H
X
10
.
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