CHEM 181 Study Guide - Final Guide: Ajinomoto, Phthalate, Menopause

71 views3 pages

harlequinmacaw120

8 May 2012

School

Department

Course

Professor

For unlimited access to Study Guides, a Grade+ subscription is required.

897wjface and 39475 others unlocked

CHEM 181 Full Course Notes

Verified Note

11 documents

Document Summary

Dashi is an extract of a seaweed known as kombu. The taste of dashi is mild but when added to other foods it brought out their flavours. Thus it was given then name umami meaning delicious . Monosodium glutamate was first sold as a table condiment called aji-no-moto (essence of taste) Msg has been accused of causing hypertension, asthma, depression, add and chinese. Glutamic acid produced through fermentation of beet sugar or corn syrup. Effects seen were fainting, rapid heartbeat, nausea and muscular twinges. Lesions in brains of mice when given msg in an amount equivalent to that found in a can of soup. But then human studies showed nothing when fed large amounts of msg. Well controlled, double blind studies concluded that msg presents no problems at the levels normally used, but a large dose may cause burning sensation, facial pressure, headache, drowsiness and weakness in a very small percentage of people.

Related Questions

Mineral Floatation

will be given a vial of sand and a vial of goethite (a coloured mineral). Add the sand to the vial of goethite, again taking note of the appearance of the mixture after itâs been shaken. Take note of how readily identifiable the different particles are. In a large glass cylinder, combine 500 mL of water with 1 mL of 10% dishwashing soap solution. Adjust the pH of this solution to ~5. Place the tube with the air stone at the bottom of the cylinder and turn on the pump as you add the mineral mixture. (NOTE: In your write up, explain the reason for the pH change. Hereâs a hint, it has to do with surfactant chemistry, like everything else in this experiment). After running the pump, take a photo that shows any changes to both the solution and the foam on top (or describe in detail). Finally, after approximately 10-15 minutes take a photo that shows the solution devoid of the goethite (or describe in detail). More soap solution can be added to sustain bubbling. Collect the foam in the tray. Rinse the foam out and through a filter funnel with large filter paper. Take note of the appearance of the filter paper after the foam has been filtered. Include these pictures in your lab report and discuss what is shown. Make certain to discuss the entire mechanism of separation.

Separation of Methylene Blue from Red Food Dye

Add 25 drops of 0.5% methylene blue solution, approximately 1 mL of 10% dishwashing soap solution and three drops of red food dye to 500 mL of water in a 1 L beaker, placed in the foil container. Mix gently to avoid producing too many bubbles before starting. Take a sample using a long Pasteur pipette and determine its absorbance at 625 nm (the Î»max of methylene blue; the spectrometer should be âzeroedâ with a cuvette of distilled water). The absorbance should be ~1.0. If it is too low add a few more drops of the methylene blue solution and check again. Place the tube (with the air stone attached) from the pump in the beaker, with the air stone at the bottom. Turn on the pump and allow the mixture to bubble. Foam overflowing is perfectly acceptable and should be collected in the provided tray to prevent too much of a mess. At 2 minute intervals, take another sample, repeating for the first 10 minutes. At 10 minutes, you may notice that there is very little foam being produced. Add another 1 mL of 10% dishwashing soap solution and allow to continue bubbling for another 5 minutes. Take a final reading at 625 nm. Then for comparison, reset the spectrometer for 525 nm (zeroed with distilled water) and measure the absorbance again. Plot this to show the decrease in absorbance.

Discuss the importance of this. Repeat the experiment using 5 mL portions of the 0.5% cetyltrimethylammonium bromide (CTAB) solution in place of the dishwashing liquid and perform the measurements at 525 nm instead of 625 nm. With this particular mixture, it will be necessary to add approximately double the amount of dye to raise the initial absorbance to a high enough value. As with the previous experiment you can add an additional 5 mL of solution at 10 minutes to continue bubbling. After taking a final reading at 15 minutes, take one at 625 nm again (after zeroing with distilled water). Compare this (including your visual observations) to the first part of the experiment. Explain the significance of the reading at the different wavelengths after 15 minutes

CHEM 181 Study Guide - Final Guide: Ajinomoto, Phthalate, Menopause

CHEM 181 Full Course Notes

Document Summary

Get access

Related textbook solutions

Chemistry: Structure and Properties

Basic Chemistry

Principles of Chemistry Molecular Approach

Principles of Chemistry Molecular Approach

Chemistry: Structure and Properties

Chemistry: A Molecular Approach

Chemistry: A Molecular Approach

Principles of Chemistry: A Molecular Approach

Chemistry: The Central Science

Related Documents

CHEM 181 Chapter : woc 20- enhancing taste with monosodium glutamate.docx

Related Questions