A 0.331-g sample of aspirin prepared in the lab was dissolved in 95% ethanol and titrated to a phenophthalein endpoint with 16.7 ml of 0.107M NaOH. Calculate moles of scetylsalicylic acid present in the aspirin sample. What mass (g) of scetylsalicylic acis is present in the sample? Calculate the percent purity of the aspirin sample.