Aspirin is 60.00% carbon, 4.48% hydrogen and 35.53% oxygen. What is
the empirical formula for aspirin?

Hi Teatea,
   
1. 
Assume 100g of material. 
   
2. 
4.48 g H x 1 mole H
          1.01g H = 4.44 moles H 
60.00 g C x 1 mole C
          12.01g C = 5.00 mole C 
35.53 g O x 1mole O
          16.00g O = 2.22 mole O 
  
3. Divide each mole number by the smallest mole number
4.44 mole H / 2.22 mole = 2.00 mole H 
5.00 mole C / 2.22 mole = 2.25 mole C 
2.22 mole O / 2.22 mole = 1.00 mole O 
   
4. 
Need all to be whole numbers, and multiply each by 4. 
2.00 moles H x 4 = 8.00 moles H 
2.25 moles C x 4 = 9.01 moles C 
1.00 mole O x 4 = 4.00 moles O 
  
Empirical Formula for Aspirin is C9H8O4
       
regards,
Jackburton