« previous next »

Author Question: A chemist wishes to carry out a gravity chromatographic separation using diethyl ether and ethanol ... (Read 30 times)

swpotter12

  • Hero Member
  • *****
  • Posts: 527
on: Aug 23, 2018

A chemist wishes to carry out a gravity chromatographic separation using diethyl ether and
  ethanol as the eluting solvents.
  (a) With which solvent should the chemist begin the elution?
  (b) What would happen if the chemist started with the other solvent?



Question 2

When measuring a refractive index, what should you do if
  (a) no dividing line between light and dark areas can be observed through the eyepiece?
  (b) the dividing line can be seen, but it is fringed with color?



dantucker

  • Sr. Member
  • ****
  • Posts: 346
Reply #1 on: Aug 23, 2018
Answer to Question 1

(a) An elution chromatography is always started with the less polar solventdiethyl ether, in
this case.
(b) The more polsr solvent (ethanol) will carry all components through the column with little
or no separation.



Answer to Question 2

(a) Either (1) use the fine or the coarse adjustment control knob on the refractometer, the
knobs that control the refractive index setting of the instrument, or, if (1) does not work, (2)
place more compound on the prism.
(b) Adjust the dispersion correction knob.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

There are more bacteria in your mouth than there are people in the world.

Did you know?

If you use artificial sweeteners, such as cyclamates, your eyes may be more sensitive to light. Other factors that will make your eyes more sensitive to light include use of antibiotics, oral contraceptives, hypertension medications, diuretics, and antidiabetic medications.

Did you know?

Russia has the highest death rate from cardiovascular disease followed by the Ukraine, Romania, Hungary, and Poland.

Did you know?

Immunoglobulin injections may give short-term protection against, or reduce severity of certain diseases. They help people who have an inherited problem making their own antibodies, or those who are having certain types of cancer treatments.

Did you know?

Drugs are in development that may cure asthma and hay fever once and for all. They target leukotrienes, which are known to cause tightening of the air passages in the lungs and increase mucus productions in nasal passages.

Gravity Works at All Scales Gravity Works at All Scales
To keep the foot under the center of gravity, the biped’s femur is angled from hip to knee. The quad To keep the foot under the center of gravity, the biped’s femur is angled from hip to knee. The quad
Measuring the Specific Gravity of Urine with a Refractometer Measuring the Specific Gravity of Urine with a Refractometer
E10 is 10% ethanol and 90% gasoline. E10 is 10% ethanol and 90% gasoline.
Pineapples carry harmful insect shell insects, safe to eat? Pineapples carry harmful insect shell insects, safe to eat?
Separation of main-band (MB) and satellite (S) DNA Separation of main-band (MB) and satellite (S) DNA
Video: Simple and Double Sugar

For a complete list of videos, visit our video library