Given in the question- 1 mole of cyclohexanol = > 1 mole of cyclohexene Molar mass 100.16 g/mol moles of cyclohexanol = .240 / 100.16= 0.002396 moles Molar mass 82.143 g/mol moles of cyclohexene formed @100 % yield = 0.002396 Molar mass 82.143 g/mol mass of cyclohexene @ 100 % = .002396 x 82.143 = 0.197g bur we have .138g so % yield = .138 / .197 = 70.0 % Ans- 70 percentage yield of cyclohexene.