Questions increased or decreased the recovery of which crys

Questions: increased or decreased the % recovery of which crystals). Use the flow diagram and equations to answer 1a. Instead of adding NaOH to the tert-methy butyl ether solution, you added HCl and did the extraction 1b. Instead of checking for acidity using pH paper, you neutralized the solution to pH= 7.0 using litmus paper. 1c. Instead of acidifying the aqueous extract with 3M HCI, you added 1M NaOH to the aqueous extract 2. Why is it important to add calcium chloride pellets before doing the rotary evaporation? 3a. What is the purpose of the rotary evaporator? 3b. What temperature is the rotary evaporator set and why? 7. (6 points) Explain how each of the following experimental errors would have ,

Solution

7. Effect of errors

1a. Instead of NaOH we added HCl to tert-butylmethyl ether : CH3Cl and tert-butanol are formed as products.

1b. excess base added in this case, would cause dehydration of tert-butanol product to butene a gas.

1c. If NaOH is added instead of HCl to aqueous phase, dehydration of tert-butanol product to butene a gas.

2. Calcium chloride is used as a dehydrating agent to remove any traces of water left in the organic phase so as to avoid dehydration or rehydration during rotary evaporation.

2a. Removal of organic solvent is done using rotary evaporator.

2b. The temperature is set at 40 oC to avoid dehydration of alcohol and loss of products.