OCHEMOS

Problem: The value of K (@25 o C) for compound A when partitioned between water and cycloheptane is 3.37. Starting with a solution of 848 g of compound A in 497 mL of water what quantity of compound A (in grams) would remain in the water layer after two successive extractions with cycloheptane each using 331 mL of cycloheptane. Solution: The issue can be easily solved using two simple steps: 1. We should find the recovery factor for two successive extractions: 2. Finding the mass of compound A that remains in water: Answer: 80.1 g of compound A would remain in the water.

Problem: When diethyl ether (CH 3 CH 2 OCH 2 CH 3 ) is treated with concentrated HBr, the initial products are CH 3 CH 2 Br and CH 3 CH 2 OH. Propose a mechanism (show electron movement using arrows) to account for this reaction. Solution: The mechanism includes two steps : protonation and SN 2 reaction: