How do you calculate the percentage by mass of carbon in carbon monoxide? Chemistry The Mole Concept Percent Composition 1 Answer anor277 Nov 7, 2016 "%C by mass"%C by mass == "Mass of carbon"/"Mass of carbon + oxygen"xx100%Mass of carbonMass of carbon + oxygen×100% Explanation: "So %C by mass"So %C by mass == (12.011*g*mol^-1)/((12.011+15.999)*g*mol^-1)xx100%12.011⋅g⋅mol−1(12.011+15.999)⋅g⋅mol−1×100% So C-=OC≡O, percentage carbon by mass is a bit under 50%50%. 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 14075 views around the world You can reuse this answer Creative Commons License