Menthol, the substance we can smell in mentholated cough drops, is composed of carbon (C), hydrogen (H), and oxygen (O).
During combustion of a 9,984g sample of menthol, it is found that 28,160g of CO2 and 11,520g of H2 is produced.
How do we calculate the mass of carbon (C) in the CO2?
Answers
Answer:
The empirical formula is C10 H20O . Explanation: We can calculate the masses of C and H from the masses of their oxides ...
Answer:
We can calculate the masses of
C
and
H
from the masses of their oxides (
CO
2
and
H
2
O
).
Mass of C
=
0.2829
g CO
2
×
12.01 g C
44.01
g CO
2
=
0.077 20 g C
Mass of H
=
0.1159
g H
2
O
×
2.016 g H
18.02
g H
2
O
=
0.012 97 g H
Mass of O
=
Mass of menthol - mass of C - mass of O
=
0.1005 g - 0.077 20 g - 0.012 97 g
=
0.01 033 g
Now, we must convert these masses to moles and find their ratios.
From here on, I like to summarize the calculations in a table.
Element
X
l
l
Mass/g
X
m
l
l
Moles
m
m
l
Ratio
m
Integers
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
−
—
—
l
l
C
X
X
X
m
l
0.077 20
m
l
l
0.006 428
X
l
l
l
9.956
X
m
10
l
l
H
X
X
X
X
l
0.012 97
m
l
l
0.012 87
m
l
l
l
19.93
X
X
l
l
20
l
l
O
m
m
m
m
l
0.010 33
m
l
l
0.000 6456
m
l
1
m
m
m
m
l
l
1
The empirical formula is
C
10
H
20
O
.