What is the percent by mass of hydrogen in aspirin, #C_9H_8O_4#?

1 Answer
Jan 17, 2018

#5.035%#

Explanation:

We first need to find the molar mass of aspirin, which is #180.157g"/"mol#. A hydrogen atom has a molar mass of #1.008g"/"mol#. There are #9# hydrogen atoms, so they have a total molar mass of #1.008*9=9.072g"/"mol#.

So, the mass of hydrogen accounts for

#9.072/180.157*100%~~5.035%#

the mass of aspirin #(C_9H_8O_4)#.