Chapter 13, Problem 68A

Interpretation Introduction

Interpretation:

On the basis of given compositions the compound is to be identified and the two possible Lewis structure of the compound is to be suggested.

Concept introduction:

According to the Lewis structure, it represents the bonding between the lone pair of electrons which may exist in the molecule and the atoms of the molecule.

Answer to Problem 68A

The compound is ${\text{C}}_{\text{3}}{\text{H}}_{\text{6}}{\text{O}}_{\text{2}}$ and the two possible compounds with this molecular formula are methyl acetate and propanoic acid

Lewis structure of Methyl Acetate

  

Lewis structure of propanoicAcid

  

Explanation of Solution

Mass percentage of carbon = 48.6 %

Mass percentage of hydrogen = 8.18%

Mass percentage of oxygen = 43.2%

Element	percentage	Atomic mass	Moles of atoms	Mole ratio	Simplest whole number ratio
C H O	48.6 8.18 43.2	12 1.0079 15.994	48.6/12.011 8.18/1.0079 43.2/15.994	4.05 8.11 2.70	3.0 6.0 2.0

The simplest whole ratio of the atom is

C: H: O = 3:6:2

The molecular formula is

  $\begin{array}{l}{\text{C}}_{\text{3}}{\text{H}}_{\text{6}}{\text{O}}_{\text{2}}\\ \end{array}$

Conclusion

The molecular formula on the basis of the given information is ${\text{C}}_{\text{3}}{\text{H}}_{\text{6}}{\text{O}}_{\text{2}}$ and the two possible compounds of the same molecular formula are methyl acetate and propanoic acid.