Chemistry - Study Mode

[#501] The Refrigerant 'FREON' is
Correct Answer

(B) Difluoro Dichloro Methane

Explanation

Solution: Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl 3 F), chlorotrifluoromethane (CClF 3 ) and tetrafluoromethane (CF 4 ).

[#502] The chemical(s) most commonly used for cloud seeding or ‘artificial rainmaking’ is/are
Correct Answer

(A) Silver Iodide

Explanation

Solution: The most common chemicals used for cloud seeding include silver iodide, potassium iodide and dry ice (solid carbon dioxide). Liquid propane, which expands into a gas, has also been used.

[#503] 'Fire-fighting clothes' are made from
Correct Answer

(B) Asbestos

Explanation

Solution: Bunker Gear or "Turnout Gear" are terms used by many firefighters to refer to their system of outer protective clothing. Fire fighter used to be made of asbestos in the past. Because of its carcinogenic properties and other harmful effects, it has slowly been replaced by other substitutes. Fire-fighting and working clothes and accessories for firemen, rescuers and industrials made of materials FR cotton, Nomex, Modacryl, FR viscose and others.

[#504] Trinitrotoluene is
Correct Answer

(D) Used as an explosive

Explanation

Solution: Trinitrotoluene, or more specifically 2,4,6-trinitrotoluene, is a chemical compound. This yellow solid is occasionally used as a reagent in chemical synthesis, but it is best known as an explosive material with convenient handling properties.

[#505] The chief source for the production of nitrogeneous fertilizers is :
Correct Answer

(A) Ammonia

Explanation

Solution: Nitrogen fertilizers are often made using the HaberBosch process which uses natural gas (CH 4 + ) for the hydrogen and nitrogen gas from the air at an elevated temperature and pressure in the presence of a catalyst to form ammonia as the end product. This ammonia is used as a feedstock for other nitrogen fertilizers, such as anhydrous ammonium nitrate and urea.