Chapter 3 - Section 3.2 - Percent Composition of Compounds - Checkpoint - Page 87: 3.2.1

b. is the correct answer.

1. Calculate the molar mass of aspirin: $ C_9H_8O_4 $ : ( 1.008 $\times$ 8 )+ ( 12.01 $\times$ 9 )+ ( 16.00 $\times$ 4 )= 180.15 g/mol 2. Now, calculate the mass percents. C: $$\frac{( 12.01 \times 9 )}{180.15 } \times 100\%= 60.00 \%$$ Therefore, the correct answer must be b.