What is the percent by mass of oxygen in #H_2SO_4#? Chemistry The Mole Concept Percent Composition 1 Answer P dilip_k Mar 24, 2016 #=65.3%# Explanation: Molar mass of #H_2SO_4=2xx1+32+4xx16=98# so percantage of oxygen #=64/98xx100=65.3# Answer link Related questions What is mole percent? Question #e2e8b Question #bc737 Question #bc73b Question #e2e8f Question #b9857 Question #b985b Question #fee41 Question #c5c01 Question #bc73f See all questions in Percent Composition Impact of this question 1666 views around the world You can reuse this answer Creative Commons License