ORGANIC CHEMISTRY PRACTICE REPORT
Name : Rudi Setiawan
Npm : E1G013100
Study Program : TIP
Group : 3
Day/Hour : Monday / 08.00-09.40
Date : 04-21-2014
LECTURER : Devi silsia, Dra., M.si
Practical object : IDENTIFICATION ALDEHYDES AND KETONES
AGRICULTURAL TECHNOLOGY LABORATORY
FACULTY OF AGRICULTURE
An aldehyde is a compound that contains a carbonyl group bonded to one or two hydrogen atoms.Most of the flavor components formed through Mailard reactions are from the aldehydes, ketones, diketones and short chain fatty acids. In addition, heterocyclic compounds containing nitrogen, sulfur or a combination of both also contribute to the flavor formation of organic matter undergoing browning reactions. However, flavor formation from aldehydes, ketones, alcohols, esters and acids from fatty-oil components in plant organic matter, naturally may occur, especially during storage, through hydroxyacid cleavage reactions to form lactone compounds, or beta reactions. oxidation and/or oxidation reactions catalyzed by lipoxygenase
Ketones are simple compounds that contain a carbonyl group and a C=O double bond. Ketones are simple compounds when viewed based on the absence of other reactive groups such as –OH or -Cl which are directly bonded to the carbon atom in the carbonyl group – as can be found for example in carboxylic acids containing the -COOH group. Examples of ketones. In ketones, the carbonyl group has two hydrocarbon groups attached to it. Again, the group can be an alkyl group or a group containing a benzene ring. Here we will focus only on ketones containing alkyl groups to simplify the discussion.
Aldehydes and ketones react with various compounds, but in general aldehydes are more reactive than ketones. Chemists took advantage of the ease of oxidation of aldehydes by developing several tests to detect this functional group. The results are easy to see. The most widely used tests for the detection of aldehydes are the Tollens, Benedict, and Fehling tests.
Aldehydes and ketones are a group of compounds that have a carbonyl group. General identification can be done by testing the reaction of 2,4-dinitrophenylhydracin. This reaction is positive for the carbonyl group of aldehyde and ketone compounds with the formation of 2,4-dinitrophenihydracin compounds in the form of yellow/red precipitates.
1.2 practical goals
️ students are able to identify and determine the reactivity of aldehyde and ketone compounds
Aldehydes and ketones contain carbonyl groups C = O. If these two groups attached to the carbonyl group is a carbon group, then the compound is called a ketone. If one of the two groups is hydrogen, then the compound is an aldehyde group. Partial oxides of alcohols give aldehydes. Secondary alcohol oxidation produces ketones. The gradual oxidation of ethanol to acetaldehyde then to acetic acid is illustrated by a molecular model (Petrucci, 1987).
Although addition reactions are common for aldehydes, only a limited number of ketones can form significant amounts of bisulfite products. Higher aldehydes behave almost the same, depending on the size of the attached group, because all of these substances have more in common the formyl group, -CHO. Acetone reacts more slowly and less widely, but the changes still exceed those observed from higher scatters. In the ketone series, which have one methyl group, the reaction is reduced (Louis, 1964).
Lignin can be hydrolyzed using nitrobenzene or a combination of ethanol and hydrochloric acid to produce vanillin, siringaldehyde, p-hydroxybenzaldehyde, alpha-ethoxypropioguaiacon, guaiasilatone, vanilyl methyl ketone or hydroxybenzoyl methyl ketone compounds. In the results of this study, chemical hydrolysis resulted in an increase in monosaccharides up to 88% sugar content, but this process is a positive control and is not expected to be widely applied because it uses concentrated and dilute sulfuric acid toxic substances (Susilaningsih, 2008).
Aldehydes, ketones and esters undergo reactions at the carbonyl group. The carbonyl group is polar and has sp . hybrid orbitals2 so that the three atoms bonded to the carbon atom lie on a plane with a bond angle of 120°. The carbon-oxygen double bond in the carbon group consists of one bond and one bond. The bond is the result of the overlap of one sp . orbital2 a carbon atom with one p orbital for an oxygen atom. While the bond is the result of overlapping the p orbital of the carbon atom with another p orbital of oxygen. Two sp . orbitals2 other than the carbon atom is used to bind other atoms. The oxygen atom of the carbonyl group still has two orbitals and is filled with two electrons, these two electrons are the 2s and 2p orbitals (Katja, 2004)
1.1 Tools and Materials
· tools used
️ spray bottle
️ beaker 100 ml/500 ml
️ measuring cup 10ml/25 ml
️ drop pipette
️ Erlenmeyer 250 ml / 100 ml
️ Test tube + rack
️ Pipette volume 5 ml
️ Stirring rod
· Materials used
️ Ethanol (alcohol)
️ universal pH indicator
1.2 work procedures
I. identification of aldehydes and ketones
1. Prepare two dry and clean test tubes
2. Test tube I : added 1 ml of aldehyde and 3.0 ml of 40% NaHSO3
test tube II : plus 1 ml of ketone and 3.0 ml of 40% NaHSO3
3. In each of the above test tubes, add 1-2 drops of alcohol and shake the tube
4. If a solid is formed, add 3 ml of distilled water to dissolve it
5. observe what happens
II. oxidation reaction
1. Enter 10 ml of acetaldehyde solution (ethanal) into a beaker with a volume of 100 ml
2. add oxidizer potassium pemanganate ( KMnO4 ) as much as 2 ml
3. stir with a stirring rod to facilitate the entry of oxygen from outside
4. measure the pH of the mixture, if the pH is acidic, it means the reaction has taken place
III. reaction of formaldehyde with protein
1. Prepare two dry and clean test tubes.
2. Add 5 ml of protein to each test tube
for test tube I : add 10 drops of formaldehyde
for test tube II : add 10 drops of acetone solution
3. compare the results of the two reactions.
RESULTS AND OBSERVATIONS
4.1 observation result
Identification of aldehydes and ketones
Aldehydes + NaHSO3+ alcohol + distilled water
Ketone + NaHSO3 + al;cohol + distilled water
Acetaldehyde + KMnO4
Ph = 4 (already formed acid)
Reaction with protein
Protein + formaldehyde
Protein + acetone
Based on the results of experiments that have been carried out, it can be defined that aldehydes existLan organic compound in which the carbonyls (carbons bonded to oxygen) are always bonded to at least one hydrogen, the structural formula for aldehydes is RCHO. Whereas ketones are organic compounds in which carbon-carbonyl compounds are linked to two other carbons, the structural formula for ketones is RCOR.
Aldehydes and ketones in water mix perfectly. They can also be recognized by their names, which end in –al for aldehydes and –on for ketones. Aldehydes and ketones also have a characteristic odor. Aldehydes have a stimulating smell and ketones smell good. In this experiment, we also experimented with using acetaladehid material which is added with KMn04, then stirred evenly so that it produces a blackish brown color (pH = 4 or an acid has formed. Meanwhile, formaldehyde is added with form a precipitate yellow lumps. While the acetone + protein produces a white precipitate clot.
Maybe in this experiment results obtained not in accordance with the existing theory. because caused by several factors, one of which is formalin and the acetone used is probably the old sample. In addition, the heating may not be perfect.
An aldehyde is a compound that contains a carbonyl group bonded to one or two hydrogen atoms. Ketones are simple compounds that contain a carbonyl group and a C=O double bond. Based on the results of experiments that have been carried out, it can be defined that aldehydes existLan organic compound in which the carbonyls (carbons bonded to oxygen) are always bonded to at least one hydrogen, the structural formula for aldehydes is RCHO. Whereas ketones are organic compounds in which carbon-carbonyl compounds are linked to two other carbons, the structural formula for ketones is RCOR. Aldehydes and ketones in water mix perfectly.
My advice is that when practicing, all the equipment or materials that will be used for practicing should be available so that they can practice well.
Katja, 2004, Organic Chemistry, Volume 2, Erlangga, Jakarta.
Louis, 1964, Organic Chemistry I, ITB Publisher, Bandung.
Petrucci, R. H, 1999, Modern Principles and Applied Basic Chemistry, Erlangga, Jakarta.
Susilaningsih, 2008, Organic Chemistry, Bina Rupa Aksara, Jakarta.