Final answer:
The empirical formula of acetic acid is CH2O, and the percent composition by mass is 40% C, 6.67% H, and 53.33% O. The empirical formula of ribose is CHO, and the percent composition by mass is 45.45% C, 9.09% H, and 45.45% O.
Step-by-step explanation:
The empirical formula of acetic acid is CH2O, and the percent composition by mass is 40% C, 6.67% H, and 53.33% O. The empirical formula of ribose is CHO, and the percent composition by mass is 45.45% C, 9.09% H, and 45.45% O.