Answer to Question #308433 in General Chemistry for Krix

Question

Percent Composition and Empirical Formula

1. The chemical analysis of aspirin indicates that the molecule is 60.00% carbon, 4.44% hydrogen,

and 35.56% oxygen. Determine the empirical formula for aspirin.

2. **Glucose is a simple sugar produced during photosynthesis. It has a molecular formula of C6H12O6.

a. Compute for the percent composition.

b. Determine the empirical formula.

Answer 1

1 Empirical formula

C. H. O

Moles. 60÷12. 4.44÷1 35.56÷16

= 5. 4.44. 2.2225

Mole ratio=5÷2.2225:4.44÷2.225:2.225÷2.225

=2.25:2:1

=9:8:4

The empirical formula is C₉H₈O₄

2(a) Percentage composition of C₆H₁₂O₆

Carbon = (12×6÷180)×100=40%

Hydrogen= (12×1÷180)×100= 6.66%

Oxygen=(16×6÷180)×100 = 53.33%

(b) C:H:O = 6:12:6

Simplest ratio =1:2:1

Empirical formula is CH₂O