The fundamental concepts of electrochemistry and Uses of Organic chemicals.

Conductors and insulators

Those substances which allow electric current to pass through them are known as conductors. For example metal, their alloy and electrovalent compounds.

The substances which do not allow current to pass through them are called non-conductors or insulators. For example glass, rubber and organic compounds such as benzene.

Mixed conductors

Those substances which conduct electric current partly electronically and partly ionic are called mixed conductors. For example ZnO and CH₂ O

Semiconductor

These consist of covalent crystals which are poor conductors in pure state and at normal temperatures. But they become good conductors either at high temperatures or in the presence of small quantities of impurities. For example germanium and silicon.

Electrolysis

When current is passed through an electrolytic solution, the electrolyte is decomposed. The type of chemical reaction carried out by passing electricity is called electrolysis.

Faraday’s laws of electrolysis

First law

The mass of substance liberated at the electrodes during electrolysis is directly proportional to the quantity of electricity that passes through the electrolyte.

Second law

When the same quantity of electricity is passed through different electrolytes, the mass of substances liberated in each case is directly proportional to the equivalent mass of the substance.

Buffer solution

Such a mixture in which PH remains constant even after the addition of a small amount of acid or base is called a buffer solution. For example, a mixture of acetic acid, sodium acetate and a mixture of HCl or NaOH.

Uses of Organic chemicals

Alcohols

Hydroxyl derivatives of aliphatic hydrocarbons are known as alcohols. For example methanol, and ethanol.

Uses of alcohols

Ethanol is used to manufacture alcoholic beverages and as a preservative for biological specimens.

Methanol is used in the manufacture of formaldehyde and to prepare methylated spirits.

Glycerol

On hydrolysis with alkali, the fats and oils produce glycerol. And also produces the salts of long-chain fatty acid soap. This reaction is called saponification. Glycerol is obtained as a by-product in the manufacture of soap.

Uses of glycerol

Glycerol is used in the preparation of soap and cosmetics.

This is used to prevent tobacco from drying out.

This is used as a sweetening agent in beverages and medicine.

This is used in making printing inks and stamp pad inks.

This is used in the manufacture of dynamite.

Phenol

Phenols are a class of organic compounds with aromatic rings.

Uses of phenol

For making Bakelite.

For the manufacture of drugs like aspirin, salicylic acid and salt.

As an antiseptic in the preparation of soaps and ointments.

For the manufacture of explosives and picric acid.

Ethers

Ethers are a class of organic compounds that contain an oxygen atom bonded to alkyl or aryl groups.

Uses of diethyl ether

Used as a general anaesthetic

Used as a refrigerant

Used as a solution for artificial silk, oil, fat etc.,

Mixed with alcohol, it is used as a substitute for petrol.

Uses of formaldehyde

Used as a preservative for biological specimens and in leather tanning.

Used to prepare Bakelite

Used as a medicine for urinary infection, urotropine.

Used to decolorize vat dyes.