Cyclopentanol can be dehydrated to form cyclopentene in the presence of an acid catalyst, such as concentrated phosphoric acid.
Cyclopentene is a volatile organic liquid with a boiling point of 44 ∘C44\text{ }^\circ\text{C}44 ∘C and a density of 0.77 g cm−30.77\text{ g cm}^{-3}0.77 g cm−3. Cyclopentanol has a boiling point of 140 ∘C140\text{ }^\circ\text{C}140 ∘C.
A student plans to prepare 6.80 g6.80\text{ g}6.80 g of cyclopentene. The expected percentage yield of this synthesis is 75.0%75.0\%75.0%.
The molar mass of cyclopentanol is 86.0 g mol−186.0\text{ g mol}^{-1}86.0 g mol−1 and cyclopentene is 68.0 g mol−168.0\text{ g mol}^{-1}68.0 g mol−1.
Calculate the mass of cyclopentanol that the student should use, writing your answer to 3 significant figures.
Describe and explain the key steps required to obtain a pure, dry sample of cyclopentene from the reaction mixture distillate, which contains both aqueous and organic layers.
The IR spectrum of the organic layer from the distillate shows a broad peak at 3200–3600 cm−13200\text{--}3600\text{ cm}^{-1}3200–3600 cm−1 and a sharp peak at 1620–1680 cm−11620\text{--}1680\text{ cm}^{-1}1620–1680 cm−1. Explain what each of these peaks indicates about the progress of the reaction.