Carbon has the unique ability to
form bonds with other atoms of carbon, giving rise to large molecules. This
property is called catenation.
Compounds of carbon, which are
linked by only single bonds between the carbon atoms are called saturated
compounds. Compounds of carbon having double or triple bonds between their
carbon atoms are called
unsaturated compounds.
Such compounds with identical
molecular formula but different structures are called structural isomers.
All these carbon compounds which
contain just carbon and hydrogen are called hydrocarbons. Among these, the
saturated hydrocarbons are called alkanes. The unsaturated hydrocarbons which
contain one or more double bonds are called alkenes. Those containing one or
more
triple bonds are called alkynes.
Unsaturated hydrocarbons add
hydrogen in the presence of catalysts such as palladium or nickel to give
saturated hydrocarbons. Catalysts are substances that cause a reaction to occur
or proceed at a different rate without the reaction itself being affected. This
reaction is commonly
used in the hydrogenation of
vegetable oils using a nickel catalyst. Vegetable oils generally have long
unsaturated carbon chains while animal fats have saturated carbon chains
Ethanoic acid is commonly called
acetic acid and belongs to a group of acids called carboxylic
acids. 5-8% solution of acetic
acid in water is called vinegar and is used widely as a preservative
in pickles. The melting point of
pure ethanoic acid is 290 K and hence it often freezes during winter in cold
climates. This gave rise to its name glacial acetic acid.
Esters are most commonly formed
by reaction of an acid and an alcohol. Ethanoic acid reacts with absolute
ethanol in the presence of an acid catalyst to give an ester
On treating with sodium
hydroxide, which is an alkali, the ester is converted back to alcohol
and sodium salt of carboxylic
acid. This reaction is known as saponification because it is used in the
preparation of soap.
Ethanoic acid reacts with carbonates
and hydrogencarbonates to give rise to a salt, carbon dioxide and water.
The molecules of soap are sodium
or potassium salts of long-chain carboxylic acids. The ionic-end of soap
dissolves in water while the carbon chain dissolves in oil. The soap molecules,
thus form structures called micelles
Detergents are generally ammonium
or sulphonate salts of long chain carboxylic acids.
Next Topic:-Science Class 10 NCERT Textbook- Lesson-5
Next Topic:-Science Class 10 NCERT Textbook- Lesson-5
