Question

Which of the following statements is/are correct for performing the microscale distillation? (Select all that apply.)

	a.	Drops should be collected at a rate of 1 drop per 1 or 2 seconds.
	b.	The pipe cleaner must be kept moist on the condenser tube.
	c.	The body of the flask should be filled just up to the neck.
	d.	The final distillation temperature should be recorded after half of the original volume has been collected.
	e.	The temperature probe tip should be inserted so that it reaches down into the liquid compound.

Answer 1

a.] For microscale distillation, good separation can be attained at the rate of 1 drop per 20-30 seconds. Therefore, this statement is not accurate.

b.] A wet/moist pipe cleaner acts as aa good cooling device and hence is used a lot of times. Hence, statement b is correct.

c.] The flask should never be more than half full or more than two third full to leave room for boiling. So this statement is wrong.

d.] Final temperature can be recorded until 90% of the original compound has been collected. Let 10% be left behind to make sure the flask doesn't run completely dry. This statement is wrong.

e.] The tip of the thermometer should reach into the lower part of the Hickman head i.e. the collection well. You should be measuring the temperature of the vapour and hence it shouldn't reach into the liquid compound. This statement is incorrect.