Question

A compound contains C, H and O as the elements. A 20.0 g-sample is comprised of 1.34 g H and also 8.00g of C. What is the empirical formula of the compound?

Answer 1

Answer:

Explanation:

Total mass of sample = 20 g

mass of H = 1.34 g

mass of C = 8.00 g

mass of O = 20 - ( 8 + 1.34 )

= 10.66 g

no of atom of H in 1.34 g

= 1.34 / atomic weight of H .

= 1.34 / 1 = 1.34

no of atom of C in 8.00 g

= 8.00 / atomic weight of C

= 8.00 / 12 = .67

no of atom of O in 10.66 g

= 10.66 / atomic weight of O .

= 10.66 / 16 = .67

Ratio of no of atoms of H , C , O in the compound

= 1.34 : 0.67 : 0.67

Divide all by .67  

= 2 : 1 : 1  ( integral ratio )

Hence empirical formula of compound

= CH₂O.