2000 x 0.25 = 500 calories from fat.
2000 x 0.75 = 1500 calories from sugar.
g fat x 9.0 cal/g = 500
g fat = about 55.6 g fat for 25%.
g sugar x 4.5 cal/g = 1500
g sugar = 333.3 g sugar for 75%.
g O2 needed for fat consumption is
2C57H114O6 x 165O2 = 114CO2 + 114H2O
mols fat = g/molar mass = about 55.6/895.5 = about 0.062
Convert to mols O2.
0.062 mols fat x (165 mols O2/2 mol fat) = about about 5 mols O2 which is 5*32 or 160 g oxygen needed to burn the fat.
g O2 needed for sugar consumption is
C6H12O6 + 6O2 --> 6CO2 + 6H2O
mols sugar = grams/molar mass = about 333/180 = about 1.85 mols sugar.
Convert to mols O2 then to grams O2.
1.85 mols sugar x (6 mols O2/1 mol sugar) = 11 mols O2 or 355 g oxygen for the sugar consumption.
Total oxygen needed = 355g for sugar + 160 g for fat = ?
Note that I've estimated here and there so you should go through and work the problem more accurately.
The typical person needs a 2000 calorie diet to sustain “normal” activity. Nowadays, a lot of the energy in American diet comes from fats and sugars. Assume that “fats” provide 9.0 calories per gram and sugars (treat as glucose) provide 4.5 calories per gram. If your “typical” person got 25 % of their energy from fats and the other 75 % from sugar, then how many grams of oxygen per day would your typical person have to consume to convert the food into carbon dioxide and water? Assume “fats” are neutral triglycerides (C57H114O6) and assume sugars are all glucose (C6H12O6).There is a 5% error interval around the correct answer. The units are grams.
1 answer