CHEMISTRY [1 Mark Question Answer]

Polyester is added to natural fiber cotton, to give terylene because this combination makes the fabric easy to clean and crease-resistant.

They extend the shelf life of a cosmetic and may prevent growth of microorganisms.

Philosopher’s stone is a legendary substance, capable of turning inexpensive metals like lead or mercury into – gold and silver. (It was not literally a stone, but a powder or potion).

Ordinary soap is wasted in hard water because hard water is one which does not lather with soap.

It is a natural pigment powder which provides a base for mineral makeup. It provides mild sun protection and as a pigment gives a white colouration to coloured ingredients.

Towards the end of the 17th Century the scientific processes involving modem Chemistry started paving paths and Alchemy today is considered pseudoscience and Chemistry regain its rightful position as a serious scientific field.

A scientist who discovered Safety lamp: : Sir Humphry Davy

A scientist who discovered Oxygen: Joseph Priestly

A scientist who discovered Atoms:
John Dalton was a British chemist and physicist. He proved that matter consists of small indivisible called ‘atoms’. For this, he proposed the atomic theory which was later on called “Dalton’s atomic theory”.

Contribution of chemistry in the field of national Defence:
Substances like gunpowder, T.N.T. (trinitrotoluene), phosgene, chemical weapons, laughing gas, etc., are all products of chemistry which contribute to the national defence.

Contribution of chemistry in the field of Industry:
To improve the efficiency and production of metals, paints, paper, plastics alloys, textile, pharmaceuticals, electroplating, cosmetics, synthetic fibres, etc.

Six products of daily use are soap, paints, pen, tooth-paste, cooking oil, potable water

The word “Alchemy” has its origin in a Greek word ‘Khemeia’ means “art of transmuting metals”. It was partly based on experimentations and partly on spiritual discipline

Chemistry is very helpful in improving the health of human beings by providing Antibiotics, Pain killers, Pencilin, Tetracycline, etc. It has provided us with Vitamins, Enzymes, Minerals, and Anesthesia (chloroform, formalene, etc.)

“The branch of science that deals with the study of the composition and the physical and chemical properties of various forms of matter is called Chemistry.”

Science is the systematic effort by human beings to control nature through experiments and observation for their own use.

Two examples of Chemical war weapons:
1. TNT
2. RDX

Two examples of Building materials:
1. Cement
2. Steel
3. Glass

Two examples of Medicines:
1. Penicillin
2. Painkillers
3. Antibiotics

Two examples of Fungicides:
1. Sulphur
2. Bordeaux mixture

Two examples of Fuel:
1. L.P.G.
2. Petrol
3. Coal

Two examples of:
Food preservatives :
1. Sodium Benzoate
2. Sodium metabisulphite
3. Sugar
4. Common salt

Alchemy and alchemists are older words for Chemistry and chemists where –alchemists transformed or created substances through a seemingly – magical process. An alchemist Nicolas Flamel claimed to transform metals into gold.

The method used for collecting ammonia gas is the downward displacement of air. This method is used for gases like ammonia which is soluble in water and lighter than air.

The tap at the base of the burette helps in removing the measured liquid dropwise.

The air regulator has holes and is used for regulating the flame.

The clamp mounted on the rod of a retort stand helps in holding the apparatus and adjusting its level upwards or downwards.

The asbestos fixed at the centre of the wire gauze initiates even distribution of heat to the bottom of the apparatus. It also prevents glass apparatus from cracking

The wooden handle at the end of the test tube being a poor conductor of heat makes holding the test tube holder easy.

Round bottom flask is preferred to flat bottom flask because in the round bottom flask heat is uniformly distributed throughout on heating.

Retort: For carrying out distillation experiments which include the distillation of acids.

Round bottom flask: In preparation of gases, where heating is required. Since the flask is round-bottomed, heat is uniformly distributed throughout on heating.

Beaker: It is used for holding pouring and mixing solutions.

Hard glass boiling tube: It is resistant to chemicals and used for special purposes. It is made of pyrex

Glass test tube: It is used for heating chemicals and studying reactions in chemicals solutions.