ARTICLE 1: ORGANIC CHEMISTRY EXPERIMENT

DETERMINATION THE NAME AND STRUCTURE OF UNKNOWN SAMPLE ORGANIC SUBSTANCE BY QUALITATIVE ANALYSIS

By

Ni Ketut Sepmiarni

Chemistry Education Department, FMIPA, UNDIKSHA

Udayana Street Singaraja, Bali

Emai: arnisepmiarni@yahoo.com

Abstract

The aim of the experiment was to determine the name and structure of organic substance that contain in unknown sample through determine physical properties namely melting point, identify component of organic compound through identification of carbon and hydrogen, identification of oxygen, identification of sulfur, nitrogen, and halogens, detect functional group such as unsaturated, aliphatic or aromatic, hydroxyl group of alcohol, fenolat group, aldehyde group, carboxyl group, ester, eter, and nitro group, and derivative compound of organic substance that contain in unknown sample. The object of this research is unknown sample (white powder) of organic substance that already prepared and only known by laboratory assistant. The method used in this experiment was qualitative analysis. The result of this research indicated that the unknown sample is benzoic acid by IUPAC name with chemical formula (C₇H₆O₂). This result was supported by the melting point 121.5^oC – 122^oC , positive content element carbon, positive contain unsaturated bond means has double bond, has carboxyl group, positive hydroxyl group of alcohol,  aromatic compound, positive of ester that indicated derivate of carboxylic acid, and produce fruit aroma.

Key word: organic compound, qualitative analysis, benzoic acid

The Word "Love"

Love is ......???
You can give comment here..,
But for me love is chemistry. Without chemistry each other, there is no love.

Love is when my heart melted  if I meet him.

TESTING ACID & BASE BY USING LITMUS PAPER

This video can be used to explain testing of acid and base solution by using Litmus paper. 

(Video from YouTube)

CHEMISTRY OF NOBLE GAS

Noble gases are a special group because it is the most stable group in the periodic table. Noble gases have electron valence configuration s2p6, except helium with electron valence configuration s2. This structure cause noble gases are unreactive. Although noble gases are stable and unreactive but, it could form compounds with some mechanisms. Beside that, noble gases are useful in human life. In this essay will explain briefly the properties of noble gases, their uses, as well as some compound of noble gases and their ways of preparation.
In periodic table, group of VIIIA also called noble gases group. In one period, the noble gas has smallest atomic radii. The elements of the noble gas group are not very   reactive because they are stable (have eight electrons in the valence shell). The noble gases are, in fact, comparatively unreactive, but some (especially xenon and krypton) are not “inert” even though that label was once applied to the noble gas.  Elements belonging to noble gases are He, Ne, Ar, Kr, Xe, and Rn (James E. House, 2008). Some properties of noble gases can be seen in the following table.

Elements belonging to noble gases are He, Ne, Ar, Kr, Xe, and Rn. First is helium (He), this element was named helium the Greek word helios, its mean “sun”. (James E. House, 2008). In 1968 Pierre Jansen found evidence of He during the total solar eclipse when he detected a new line in the solar spectrum. In 1895, Ramsay discovered He in the uranium mineral cleveite. At the same time, the Swedish chemists Cleve and Langlet discovered He in cleveite. In 1907 Rutherford and Royds demonstrated that alpha particles are He nuclei (Yulianto Mohsin, 2005). It has long been related to nuclear chemistry because of the formation of alpha particles (  4He2+) during the decay of heavy nuclei.