6.42 x 101 g/mL
Molar mass of ibuprofen is = 206g/mole 0.525 moles ibuprofen x (206g ibuprofen/1mole ibuprofen) = 108g ibuprofen
1 cup is 250 gm. -So 206 gm is about 4/5 of a cup.
Given C13H18O2 (which is ibuprofen, by the way) the molar mass is 206g/mol. (This figure is derived from adding the atomic masses of all the constituent atoms of that compound.) The percent composition by mass of the hydrogen in ibuprofen is 18/206=0.087, which is 8.7%. The given mass is 44g, so 8.7% of 44 = 3.83g hydrogen.