Question

The molecular mass of an organic compound is 90 and its %age composition is C-26.6%,O=71.1%,H=2.2%.Determine the formula of the compound?

Answer 1

Let be
The molar mass of compound =100g
Moles of C in Compound =26.6/12=2.216
Moles of O in compound=71.1/16=4.44
Moles of H in compound=2.2/1=2.2
Ratio of mole of C, O and H is 1 : 2 :1
So,
Empirical Formula = CHO2
​Empirical formula mass=12 g + 1 g + 32 g = 45 g
Molecular formula = (empirical formula)n
n=Molar mass/empirical formula mass
n=90 /45 = 2
The molecular formula would be (CHO2)2 = C2H2O4

Answer 2

Answer:C2H2O4

Explanation:

Let the molar mass of compound is 100 g

Number of moles of C in compound = 26.6/12 = 2.216

Number of moles of O in Compound = 71.1/16 = 4.44

Number of moles of H in compound = 2.2/1 = 2.2

Simple whole number ratio of mole of C, O and H is 1 : 2 :1

Empirical Formula = CHO2

​Empirical formula mass = 12 g + 1 g + 32 g = 45 g

Molecular mass of the compound is 90 g

Molecular formula = (empirical formula)n

n = Molar mass/empirical formula mass

n = 90 /45 = 2

So the molecular formula would be (CHO2)2 = C2H2O4