Question

A good yield of photosynthesis for agricultural crops in bright sunlight is 20 kg of carbohydrate (for example, sucrose) per hectare per hour. (1 hectare= 10⁴ m²) The net reaction for sucrose formation in photosynthesis can be written as:

12 CO_{2 (g)} + 11 H₂0_(l) --->C₁₂H₂₂O_11(s) +12 O_{2 (g)}

A. Use the standard enthalpies of formation to calculate D_rH^* for the production of 1 mol of sucrose at 25 degrees celsius by the reaction above. (show work).

B. Calculate the energy equivalent of photosynthesis that yields 20 kg of sucrose (hectare^-1 h^-1). (show work).

C. Bright sunlight corresponds to radiation incident on the surface of Earth at about 1 kW m^-2. What percentage of this energy can be "stored" as carbohydrate in photosynthesis? (show work)

Answer 1