Qualitative reactions organic materials, ions, and cations to determine the presence of various compounds using available in most cases simple methods.They can be carried out by means of indicators, hydroxides and oxides.The science that studies the properties and structure of various substances, referred to as "chemistry".Qualitative reactions are part of the practical section of this science.
Classification of inorganic substances
All substances are divided into organic and inorganic.The former include such classes of compounds, such as salts, hydroxides (base, acid and amphoteric) and oxides, here also include simple compounds (SІ2, I2, N2 and the other consisting of a single element).
Salts consist of cations of any metal, and an anion of an acid residue.The composition of the acid molecules include H + cations and anions of acidic residues.Hydroxides are composed of metal cations and anions in the form of hydroxyl group OH-.Composition molecules oxides includes atoms of two chemicals, one of them is necessarily oxygenation.They can be acidic, basic and amphoteric.As apparent from their names, they are capable of forming different classes of agents in certain reactions.Thus, acid oxides by reaction with water to form acid and basic - a base.Amphoteric, depending on conditions, may exhibit properties of both types of oxides.Such compounds include iron, beryllium, aluminum, tin, chromium, and lead.These hydroxides are also amphoteric.To determine the presence in solution of various inorganic substances are used for qualitative reactions ions.
variety of organic substances
This group includes chemical compounds composed of molecules which must include Carbon and Hydrogen.They can also contain atoms with oxygen, Nitrogen, Sulphur and many other elements.
They are divided into the following main classes: alkanes, alkenes, alkynes, organic acids (nucleic fatty saturated, amino acids, etc.), aldehydes, proteins, fats and carbohydrates.Many qualitative reactions on organic matter carried out using a variety of hydroxides.For these reagents can be used such as potassium permanganate, acid oxides.
Qualitative reactions for organic substances
presence of alkanes is mainly determined by process of elimination.If you add potassium permanganate, it will not discolor.Burning these materials flame light blue.Alkenes can be detected by the addition of bromine water or potassium permanganate.Both of these agents interacting with them discolored.The presence of phenol can also be determined by adding a solution of bromine.He discolored and precipitate fall.Furthermore, the presence of the substance can be detected with a solution of ferric chloride, which upon reaction with it gives a violet-brown color.Qualitative reactions for organic substances class alcohol is to add sodium him.In this case, the evolved hydrogen.Burning alcohol is accompanied by a light blue flame.
Glycerin can be identified by a hydroxide Cuprum.This formed glycerate, which give a solution cornflower blue color.You can determine the presence of aldehydes using oxide Argentum.As a result of this reaction produces pure Argentum, which precipitates.
also a qualitative reaction for aldehyde, which is implemented via copper hydroxide.For its implementation is necessary to heat the solution.At the same time he must first change the color blue to yellow and then to red.The proteins can be detected using a nitrate acid.Consequently, a yellow precipitate.If we add hydroxide Cuprum, it will be purple.Qualitative reactions for organic substances of Class acids is carried out using litmus or ferric chloride.In both cases, the solution changes color to red.If we add sodium carbonate, releasing carbon dioxide.
Qualitative reactions on cations
They help to determine the presence of ions in the solution of any metal.Qualitative tests on acid are to identify cation of H +, which is included in their composition.This can be done in two ways: by using litmus or methyl orange.First in the acidic environment it changes its color to red, the second - in pink.
cations of lithium, sodium and potassium can be distinguished by their flame.First lit in red, the second - the yellow, the third - the violet flame.Calcium ions are detected method of adding solutions of carbonates, whereupon a white precipitate.
Qualitative reaction to anions
The most common of them - the identification of OH, whereby you can learn to be present in a solution of the base.This requires indicators.It phenolphthalein, methyl orange, litmus.The first in this environment takes on a crimson color, the second - yellow, third - blue.
