A 1.375 g sample of mannitol, a sugar found in seaweed, is burned completely in oxygen to give 1.993 g of carbon dioxide and 0.9519 g of water. The empirical formula of mannitol is

Question

Quizplus · Accepted Answer

To find the empirical formula, calculate the moles of carbon, hydrogen, and oxygen in the products. From 1.993 g of CO2, there are 0.0453 moles of C. From 0.9519 g of H2O, there are 0.1056 moles of H. The remaining mass is oxygen, which is 1.375 g - (mass of C + mass of H), giving 0.0228 moles of O. The simplest ratio of C:H:O is 3:7:3, corresponding to the empirical formula C3H7O3.

A 1375 G Sample of Mannitol, a Sugar Found in Seaweed