Chapter 3 - Section 3.2 - Percent Composition of Compounds - Checkpoint - Page 87: 3.2.2

e) is the correct answer.

1. Calculate the molar mass of aspirin: $ NaHCO_3 $ : ( 22.99 $\times$ 1 )+ ( 1.008 $\times$ 1 )+ ( 12.01 $\times$ 1 )+ ( 16.00 $\times$ 3 )= 84.01 g/mol 2. Now, calculate the mass percents. Na: $$\frac{( 22.99 \times 1 )}{84.01 } \times 100\%= 27.37 \%$$ Therefore, the correct answer must be e).