Answer:
C10H8
Explanation:
To answer this question, we need to know the atomic masses of carbon and hydrogen. The atomic mass of carbon is 12 amu while that of hydrogen is 1 amu. We start answering the question by dividing the percentages of these elements by their atomic masses.
H = 6.25/1 = 6.25
C = 93.75/12 = 7.8125
We proceed to divide both by the smallest number. This is 6.25
H = 6.25/6.25 = 1
C = 7.8125/6.25 = 1.25
The ratio of both is 1:1.25.
To make a whole number out of these, we multiply through by 4 and that gives 4:5
The empirical formula is thus C5H4
Now, we calculate the molecular formula:
(C5H4)n = 128.18
(5(12) + 4(1))n= 128.18
(60+4)n = 128.18
64n = 128.18
n = 128.18/64
n = approximately 2
The molecular formula is thus C10H8
