Question

g) i) A compound of carbon, hydrogen and oxygen is found to contain 40% of carbon , 6.7%
of hydrogen and 53.3 of oxygen. Calculate its empirical formula. If its vapour density is
30, calculate the molecular formula. (C =12, 0 = 16 ,H = 1]
(3)​

Answer 1

Answer:

emprical formula is CH2O

molecular formula is C2H4O2

Explanation:

note vapor density ×2 = molar mass

therefore 2×30 = 60

so the molar mass is 60

but to get the empical formula

divide all compostion with their various mass number

which is 40/12 for carbon = 3.3

6.7/ 1 for hydrogen = 6.7

53 3 / 16 fir oxygen =3.3

now divide through with the lowest which is 3.3

then u get 1 for carbon

2 for hydrogen

1 for oxygen

which is CH2O

den to get the molecular formula

(CH20)n=60

30n=60

so n=2 so u have

(CH2O)2 which is also C2H4O2 .......

thats it as sinple as that