Essay About Positive Test And Waste Disposal

6b Procedures
Procedure
If an unknown is a solid, a MP should be taken. IR spectra should be run on all unknowns.
Determine if you have an aldehyde or ketone
Also check for C=C or aromatic groups
For liquids, determine BP
Run 3 experiment simultaneously
Compound known to give positive test, negative test, and on the unknown.
Tollens Test (Test for aldehydes)
Place a few mL of 10% (aq) NaOH in 4-5 clean test tubes and heat them in a water bath while preparing the Tollens reagent.
Place 1mL of Tollens solution A (5% (aq) silver nitrate) in a test test tube.
Add 0.5mL of Tollens solution B (10% NaOH in water)
A grey precipitate of silver oxide (Ag2O) will form
Enough 10% (aq) ammonia should be added to dissolve the silver oxide.
Shake the mixture
Dilute the solution to ~5mL
Empty the test tubes of NaOH solution, rinse them with water, and add 0.5mL of Tollens reagent to each.
Add 1 drop of the substance to be tested by allowing it to run down the inside of the test tube, or add ~10mg in the case of a solid.
Set the tubes aside for a few minutes without shaking.
If no rxn occurs, warm the mixture briefly in the water bath.
A positive test consists of the formation of a silver mirror in the test tube.
Waste Disposal – Add nitric acid to Tollens reagent and neutralize with sodium carbonate
Schiffs Test (Distinguishing aldehydes from ketones)
Add 1 drop of unknown to 0.7mL of Schiffs reagent and slightly heat the solution.
A magenta color will appear within 10 minutes for aldehydes.
Compare the colors produced by a known ketone and a known aldehyde.
Iodoform Test (Distinguish methyl ketones from other ketones)
If the substance to be tested is water-soluble, dissolve 1 drop of the liquid or ~15mg of a solid unknown in 0.5mL of water in a test tube.
Add 0.5mL of 10% (aq) NaOH and then, slowly, 0.75mL of the iodine solution.
If the substance is