The percent composition of a compound with the empirical formula CO2 can be determined by calculating the percentage by mass of each element in the compound.

The molar mass of CO2 is 44.01 g/mol, which is the sum of the atomic masses of one carbon atom (12.01 g/mol) and two oxygen atoms (16.00 g/mol each).

The percent composition of CO2 is:

% C = (12.01 g/mol C / 44.01 g/mol CO2) * 100% = 27.28%

% O = (2 * 16.00 g/mol O / 44.01 g/mol CO2) * 100% = 72.72%

Therefore, the percent composition of the compound with empirical formula CO2 is 27.28% carbon and 72.72% oxygen.