You are working in an alternative fuels laboratory and have been asked by your supervisor to determine the efficiency of photosynthesis for a plant that is being considered as a source of biofuels. You know that the plant produces the equivalent of 24 kg of sucrose per hectare per hour. You also know that sun supplies energy at a rate of 1.0 kilowatt per square meter of surface area. Assume that sucrose is produced by the reaction: 12 CO3 (g) + 11 H2O (g) ? C12H22O11 (s) + 12O2 (l) ? H = -5640 kJ

Respuesta :

Explanation:

Moles of sucrose = [tex]\frac{\text{mass of sucrose}}{\text{molecular weight}}[/tex]

                       = [tex]\frac{24 kg \times 1000 g/kg}{342.3 g/mol}[/tex]

                        = [tex]\frac{70.114 mol}{hr-ha}} \times \frac{1 ha}{10000 m^{2}} \times \frac{1 hr}{3600 s}[/tex]

                        = [tex]1.948 \times 10^{-6} mol/(m^{2}s)[/tex]

Energy required for photosynthesis = 5640 kJ/mol

Energy needed to produce 24 kg sucrose

         = Energy required for photosynthesis x Moles of sucrose

          = [tex](5640 kJ/mol) \times [1.948 x 10^{-6} mol/(m^{2}s)][/tex]

          = [tex]0.01098 kJ/(m^{2}s)[/tex]

Energy supplied from sun = [tex]1 \frac{kW}{m^{2}}[/tex]

                                            = 1 [tex]kJ/(m^{2}s)[/tex]

Efficiency for photosynthesis = [tex]\frac{\text{Energy needed to produce 24 kg sucrose}}{\text{Energy supplied from sun}}[/tex]

                              = [tex]\frac{0.01098 kJ/(m^{2}s)}{1 kJ/(m^{2}s)}[/tex]

                             = [tex]0.01098 \times 100[/tex]

                              = 1.098%

Thus, we can conclude that efficiency of photosynthesis for a plant that is being considered as a source of biofuels is 1.098 %.