Chemistry in Everyday Life

This method is used for sterilising  spices whose flavour changes with heating. It inhibits sprouting potatoes and extends shelf life of strawberries and mushrooms.

Drugs that are used as pain relievers are called analgesics.

Aspirin and analgin are common drugs, that are used to reduce body temperature.

Tranquilizers reduce anxiety and tension. They are of two types, sedatives and anti-depressants. 

Tranquilizers reduce anxiety and tension. They are of two types, sedatives and antidepressants.

Tension and mental stress escalate the level of acid in bile juice. This hyperacidity can be combated using bases like calcium carbonate, magnesium hydroxide or aluminium hydroxide, in the form of tablets or aqueous suspensions. These react with hydrochloric acid in the stomach and neutralize it partially. Gelusil and Digene are two examples of antacids.

Antiseptics can be used to kill microorganisms  or prevent their multiplication. Antiseptics do not harm the living tissues. Therefore, they can be applied on cuts and wounds. Dettol, cetavelon, savlon, acriflavin, gentian-violet, mercuro chrome, boric acid and potassium permanganate are some examples.

It is an antiseptic. An antiseptic is used to kill bacteria or prevent their multiplication. Antiseptics do not harm the living tissues. Therefore, they can be applied on cuts and wounds.

A true dye should be fast to light and washing when fixed. For this, it must be resistant to water, acid and alkali .

Acid dyes are sodium salts of sulphonic acid and nitrophenols. They are used for dyeing animal fibres such as wool and silk, but not vegetable fibres like cotton. The dye solution is acidified with sulphuric or acetic acid.

Cold cream is an emulsion where the oil component is predominant. Oils may be almond oil, lanolin oil, paraffin oil and bees wax. Cold creams also contain water, a little perfume oil and borax. This borax enables emulsification.

These are water insoluble coloured compounds. They can be reduced to colourless (leuco) compounds, that are soluble in alkali and are easily reoxidized to give the dye. These dyes dye both animal and vegetable fibres directly. Mostly they are used for cotton fibres. The cloth treated with alkali is oxidised by air which makes the dye return to the insoluble form. For example: Indigo

Bleaching creams lighten or bleach dark skin. Skin colour is determined by melanin formation. Bleaching creams act on melanin and reduce the normal pigmentation of the skin.

It is about five times more powerful than talc in absorbing water. Hence it is often used to enhance absorbency and lightness of powders.

These are essential oils or synthetic substances or both. They constitute 2 -10% of the perfume and impart a pleasant smell to the perfume. Blending many odouriferous components will give a harmonious fragrance.

It is an edible colour and is not used as a preservative. Food colours are used in, ice creams, dairy products, sweet meat, soft drinks, confectionery, etc.. These colours are also used in oral medicines like capsules, tablets, syrups and liquids, to improve their appearance.

Antioxidants prevent rancidity in oils and fats. For example, butylated hydroxy anisole is a very common antioxidant. Vitamin-E is a natural antioxidant.

Transparent Soaps contain glycerol or alcohol. These are obtained by dissolving soap in alcohol and evaporating the solvent alcohol.

They are produced in the fibre itself during dyeing. For example, a cloth is soaked in an alkaline solution of b - naphthol and dipped in a diazonium salt solution. Azodye is produced on the fibre due to coupling.

Mordant is any substance that can be fixed to fibre and later dyed on. Hydroxides or basic salts of chromium aluminium or iron are examples. Tannic acid is a suitable mordant for basic dyes. The fabric is first dipped into the solution of mordant and then in the dye solution. An insoluble coloured complex called lake is obtained. It is insoluble and fast to washing.

Chemotherapy is the use of chemicals or drugs, to selectively destroy infectious micro-organisms without destroying the live tissues, or the host.