This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: A student started with 100 mg of an unknown solid and recrystallized this material from water. The ... (Read 63 times)

Destiiny22

  • Hero Member
  • *****
  • Posts: 557
on: Aug 23, 2018
A student started with 100 mg of an unknown solid and recrystallized this material from water. The weight of the crystals they isolated was 27 mg. Explain why the student might have obtained this result and what the student can do to try to correct the problem.

Question 2

A student started with 100 mg of an unknown solid and recrystallized it from water. The weight of the crystals isolated was 120 mg and the melting point range was very broad and lower than the literature value. Explain the problem that the student encountered and how the student can solve it.


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

14vl19

  • Sr. Member
  • ****
  • Posts: 310
Reply #1 on: Aug 23, 2018
Answer to Question 1

The hot solution was probably not saturated and therefore recrystallization would be inefficient. They should attempt to obtain a second crop of crystals by concentrating the mother liquors.

Answer to Question 2

The crystals are most likely wet with the solvent used for recrystallization. The student should let the crystals dry until the weight is constant and then recheck the melting point.


Destiiny22

  • Member
  • Posts: 557
Reply 2 on: Aug 23, 2018
Excellent

xoxo123

  • Member
  • Posts: 335
Reply 3 on: Yesterday
:D TYSM

« previous next »
 

Did you know?

All patients with hyperparathyroidism will develop osteoporosis. The parathyroid glands maintain blood calcium within the normal range. All patients with this disease will continue to lose calcium from their bones every day, and there is no way to prevent the development of osteoporosis as a result.

Did you know?

The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."

Did you know?

Children with strabismus (crossed eyes) can be treated. They are not able to outgrow this condition on their own, but with help, it can be more easily corrected at a younger age. It is important for infants to have eye examinations as early as possible in their development and then another at age 2 years.

Did you know?

Approximately one in four people diagnosed with diabetes will develop foot problems. Of these, about one-third will require lower extremity amputation.

Did you know?

According to the National Institute of Environmental Health Sciences, lung disease is the third leading killer in the United States, responsible for one in seven deaths. It is the leading cause of death among infants under the age of one year.

Water Water
Is breathing water dangerous? How do you know? Is breathing water dangerous? How do you know?
Hydrogen-bond donors and acceptors in water Hydrogen-bond donors and acceptors in water
Water consumption by type of use Water consumption by type of use
Water-based Diseases Water-based Diseases
Video: Double Vacuum Process (Illustration No Audio)

For a complete list of videos, visit our video library