Can you help me with these questions please What effect would each of the follow
ID: 490336 • Letter: C
Question
Can you help me with these questions please What effect would each of the following operations have on the success of the recrystallization of benzoic acid from hexanes? Explain your answers. a. The hot solution containing the dissolved benzoic acid is immediately placed in an ice bath. b. After recrystallization has taken place, the cold solution is vacuum filtered and product crystals are collected on a Buchner funnel, then the crystals are washed with hot hexanes. A student recrystallizes 5 g of a solid and isolates 3.5 g as the first crop. She then isolates a second crop of 1.2 g solid from the filtrate. a. What is the percent recovery in the first crop? b. What is the total percent recovery?Explanation / Answer
1) Slow cooling is needed for producing good crystals. When a hot solution is placed in an ice bath, precipitation may occurs and significantly reduces the crystalisation and purity
2)The product will redissolve in hot hexane and this reduce the yield of recrystallization.
7a) recovery in first crop=
3.5*100/5=70
7b) Total recovery = (3.5+1.2)*100/5= 97
/5