Final answer:
One carbon dioxide molecule combines with a 5-carbon compound to produce two 3-carbon compounds in the process of photosynthesis, and 3 moles of carbon dioxide will produce 90 grams of glucose.
Step-by-step explanation:
When a carbon dioxide molecule combines with a 5-carbon compound, this is usually referring to the Calvin cycle in photosynthesis. In the Calvin cycle, each CO2 molecule is attached to a 5-carbon sugar (ribulose bisphosphate), and through a series of reactions, it is ultimately converted into two 3-carbon compounds known as 3-phosphoglycerate (3PGA). Therefore, each CO2 molecule results in the production of two 3-Carbon compounds.
Regarding the question of using 3 moles of carbon dioxide in the photosynthesis reaction, it is part of the photosynthesis equation where 6 molecules of carbon dioxide react with 6 molecules of water in the presence of sunlight to produce a single molecule of glucose (C6H12O6) and six molecules of oxygen. The molar mass of glucose is 180 g/mol. So, using stoichiometry, 3 moles of CO2 will produce half a mole of glucose, which weighs 90 g (0.5 mol x 180 g/mol).