Question

Bxam 1 a1. 12,13.15) Name ancte Warcla CHM 2211L TheAllwingquetionspertain to de F nctional Group Ilmukanon Expert w. 1. Refer to the following list of possible unknowns when answering dis tion October 10,201ㄱ n the each bax below by Indicaning if the nest was positive or negartive(+or -) and what funtional groups are being tested for in eack seat a) Agse, RESULTS was evident Greupe belng lested Considering the above information identify the unknown. pts for filling the table conmetly and 24-DNP Be/CO Anhydride RESULTS was evident was oblained evident Functional Groups being testerd Considering the above information identify the unknown. 3 pts for filling the table corroctly and pts for correctly ideretityling unlenows.

Answer 1

These tests are very well known to analyze the presence of functional group in an unknown compound.

1.) 2,4-DNP test is conducted to testing presence of aldehyde or ketone functional group in unknown compound, if you get yellow-orange precipitate that means aldehyde or ketone functional group is present in given compound or if precipitate does not formed then its negative test for the same.

2.) Br₂/CCl₄ is used to detect unsaturation in the given compound such as alkene or alkyne, but it will not react with compound having only aromatic group. Brown colour of bromine get decolourise in the presence of double or triple bond (unsaturation).

3.) Chromic anhydride test: This test is conducted for detection of aldehyde, primary and secondary alcohols. Chromic anhydride oxidizes these groups to carboxylic acid group and after oxidation blue-green colour appears, which confirms the presence of above mentioned functional groups. If it shows brownish colour then none of the above mentioned functional group and ketone may present.

4.) Alcoholic AgNO₃: Silver nitrate test is conducted to confirm the presence of alkyl halide in the given compound. Aryl halide will not be detected by this test. Depending on which alkyl halide is there, colour f the precipitate will show accordingly. For example Cl^-, Br^-, I^- will form AgCl, AgBr and AgI which shows white, pale cream and pale yellow precipitate respectively. To confirm the silver halide, ammonia solution is added to these precipitate AgCl will solubilized and gives clear solution while AgBr and AgI will not. Hence, one can easily make out which alkyl halide is present in given compound.

5.) Solubility in 5% HCl solution: all basic compound will solubilize in 5% HCl solution such as aniline, alkyl amines

6.) Solubility in 5% NaOH solution: all carboxylic group, phenol group consisting compound will form sodium salt and gets solubilized. Phenols are acidic in nature.