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General Science - Chemistry (Compound):

Written By STPORTAL on Sunday, March 18, 2012 | 2:46 PM


General Science - Chemistry (Compound):
 
Compound

Compound is a substance formed from two or more elements, with a fixed ratio determining the composition. For example, water is a compound made out of hydrogen and oxygen in the ratio of two to one.
mixture is the product of a mechanical blending or mixing of chemical substances like elements and compounds, without chemical bonding or other chemical change, so that each ingredient substance retains its own chemical properties and makeup. While there are no chemical changes in a mixture, physical properties of a mixture, such as its melting point, may differ from those of its components. Mixtures can usually be separated by mechanical means.

There are different types of Compounds are Acids, Bases, Salts, Oxides and organic compounds.

 
Acids
An acid (represented by the generic formula AH) is typically a water-soluble, sour-tasting chemical compound. An acid always has a pH of less than 7 and turns litmus red. It is a molecule or ion that contains hydrogen or that is able to give up a proton to a base, or accept an unshared pair of electrons from a base. An acid reacts with a base in a neutralization reaction to form a salt. Acids are electrolytes and react violently with metals to release hydrogen.
Acid
Remarks
ascetic acid
vinegar
amino acid
basis of protein
ascorbic acid
Vitamin C
carbolic acid/phenol
disinfectant
citric acid
citrus fruits
nitrohydrochloric acid(aqua regia)
dissolving gold and platinum
RNA/ ribonucleic acid
essential for protein synthesis
sulphuric acid
corrosive acid, wide applications
tartaric acid
used in baking powder
carbonic acid
carbonated beverages
DNA/ deoxyribonucleic acid
basis of chromosomes, so genetic transmission
formic acid
ants
lactic acid
sour milk
malic acid
unripe apples
nitric acid/aqua fortis
used in explosives and rocket fuels
prussic acid/ hydrocynic acid
poison
salicylic acid
basis of aspirin
tannic acid/tannin
found in tea
uric acid
in large amounts in the urine of birds and reptiles
oxalic acid
spinach

Bases
A base is a chemical compound that will neutralize an acid and form a salt + water. Bases are typically water-soluble, bitter tasting, turns litmus blue and always have a pH greater than 7 in solution. A base is able to take up a proton from an acid or able to give up an unshared pair of electrons to an acid. e.g. baking soda , sodium carbonate etc.

pH is a measure of effective concentration of hydrogen ions in a solution.

Litmus: A mixture of pigments extracted from certain lichens that turns blue in basic solution and red in acidic solution.

Salt
a salt is a neutral compound composed of cations bound to anions. They are typically the product of a chemical reaction between; base and an acid, forming a salt + water, or metal and an acid, forming a salt + hydrogen, or an acid forming oxide and a base forming oxide, forming a salt.

A cation is a positively charged ion. Metals typically form cations where as anions are negatively charged ion.


Organic compound
These contain carbon chemically bound to hydrogen. They often contain other elements (particularly O, N, halogens, or S). Organic compounds were once thought to be produced only by living things.


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