Calculate the percentage by mass of carbon CO2

This is the total weight of CO2. Now, to know the percent composition of Carbon and Oxygen. We will divide their weight with the total weight of CO2. % C = 12.01/44.01 = 0.2729 = 27.29% (we will divide 0.2729 with 100 to take the percentage). % O = 32.00/44.01 = 0.7271 = 72.71 %O in CO2