Question

The molecular mass of an organic compound is 90 and it's percentage composition is c-26. 6%;O=71.1%and H=2.2%.Determine the molecular formula of the compound.

Answer 1

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

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

Hope this helps!!