The balanced reaction for photosynthesis is as follows;
6CO₂ + 6H₂O --> C₆H₁₂O₆ + 6O₂
stoichiometry of CO₂ to C₆H₁₂O₆ is 6:1
Number of moles of CO₂ reacted - 7.03 g/ 44 g/mol = 0.16 mol
number of C₆H₁₂O₆ moles formed - 0.16 mol / 6 = 0.027 mol
Mass of C₆H₁₂O₆ formed - 0.027 mol x 180 g/mol = 4.86 g
Actual yield of C₆H₁₂O₆ - 3.92 g
percent yield of C₆H₁₂O₆ = actual yield / theoretical yield x 100%
= 3.92 g/ 4.86 g x 100%
percent yield = 80.7%