Question

Green plants use light from the Sun to drive photosynthesis. Photosynthesis is a chemical reaction in which water H2O and carbon dioxide CO2 chemically react to form the simple sugar glucose C6H12O6 and oxygen gas O2 . What mass of carbon dioxide is consumed by the reaction of 5.4g of water? Round your answer to 2 significant digits.

Answer 1

Solution-

Chemical reaction in photosynthesis is as follows

6CO₂ + 6H₂O —> C₆H₁₂O₆ + 6O₂

Amount of water consumed= 5.4 g

No. of moles of water consumed = 5.4 / 18 moles = 0.3 moles

From the chemical reaction it is clear that

Since   6 moles of H₂O consumed = 6 moles of CO₂ are consumed

Therefore 0.3 moles of H₂O consumed = 0.3 moles of CO₂ consumed

So the amount of CO2 consumed = 0.3 moles

                                                      = 0.3 x 44 g = 13.2 g

                                                      = 13 g (2 significant digits)

Thus. 13 g mass of carbon dioxide is consumed by the reaction of 5.4g of water in photosynthesis.