Explore topic-wise InterviewSolutions in .

 NaF

For compounds containing ions of same charge, lattice energy INCREASES as the SIZE of ions decreases. Thus, NaF has HIGHEST lattice energy.

 Oxygen

Water POLLUTION in river or any other water BODY is measured by amount of DISSOLVED oxygen.

 CALCIUM PHOSPHATE

 ACETIC acid

Vinegar is an AQUEOUS solution of acetic acid and trace CHEMICALS that may INCLUDE FLAVORINGS.

 NITROGEN

Air is not the "ideal" breathing MIXTURE for diving as with a concentration of approximately 79 percent nitrogen, compressed air poses two potential problems for all divers: SUSCEPTIBILITY to nitrogen narcosis and at deeper depths; and decompression sickness. So divers use Nitrox, a gaseous mixture of nitrogen and oxygen. It is also known as ‘ENRICHED Air.’

 Sommerfeld

Sommerfeld modified Bohr's theory. According to him ELECTRONS move in elliptical orbits in addition to CIRCULAR orbits.

 Mg²⁺

Chlorophyll is the GREEN PIGMENT found in most PLANTS, which is responsible for light absorption to PROVIDE energy by PHOTOSYNTHESIS. Chlorophyll contains magnesium ion.

 Tungsten

Tungsten is the HARDEST METAL AMONG the FOLLOWING.

 Nitrogen

AIR is the name given to the atmosphere USED in breathing and photosynthesis. DRY air CONTAINS roughly (by VOLUME) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.

 0.1 “ 5% CARBON

Steel CONTAINS 0.1 – 5% carbon.

 Pyridine

Denatured alcohol or methylated spirits is ethanol that has additives to make it undrinkable (poisonous), to discourage recreational consumption. In some cases it is also dyed. Denatured alcohol is used as a solvent and as fuel for spirit BURNERS and camping stoves. Because of the diversity of industrial uses for denatured alcohol, hundreds of additives and denaturing METHODS have been used. The main additive has traditionally been 10% methanol, giving rise to the term “methylated spirit.” Other typical additives include isopropyl alcohol, acetone, methyl ETHYL ketone, methyl isobutyl ketone, and denatonium. Completely denatured alcohol must be made in accordance with the following formulation: with every 90 parts by volume of alcohol MIX 9.5 parts by volume of WOOD naphtha or a substitute and 0.5 parts by volume of crude pyridine, and to the resulting mixture add mineral naphtha (petroleum oil) in the proportion of 3.75 litres to every 1000 litres of the mixture and synthetic organic dyestuff (methyl violet) in the proportion of 1.5 grams to every 1000 litres of the mixture.

 N₂O

N₂O is not a GREEN HOUSE GAS.

 It contains MAXIMUM content of WATER vapour

Air is SAID to be saturated when the amount of water vapour in the air is the maximum possible at an existing temperature and pressure. Air is said to be saturated at 100 PERCENT RELATIVE humidity when it contains the maximum amount of moisture possible at that specific temperature.

 Animal wastes

Biogas typically refers to a gas PRODUCED by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and KITCHEN waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as BIOMASS, manure, sewage, municipal waste, green waste, plant material, and crops. Biogas comprises primarily methane (CH₄) and CARBON dioxide (CO₂) and may have small amounts of hydrogen sulphide (H₂S), moisture and siloxanes.

 NO₂, O₃ and peroxy ACETYL nitrate in the presence of Sunlight

Photochemical smog is a unique type of air pollution which is caused by reactions between sunlight and pollutants like hydrocarbons and nitrogen DIOXIDE (NO and NO₂). Other components of the photochemical smog include Ozone (O₃) formaldehyde, peroxy BENZOYL nitrate (PBzN), peroxy acetyl nitrate (PAN) and acrolein.

 Ethylene

Ethylene gas, acetylene gas LIBERATED from CALCIUM carbide, and ethephon are some of the commercial ripening AGENTS used successfully in the trade and they have been widely studied for their effectiveness on initiating and ACCELERATING the ripening process and their effect on fruit quality and health related ISSUES.

 ARSENIC

Surface WATER is a BETTER source of DRINKING water because it is poor in arsenic.

 Carbon monoxide and nicotine

Particulate matter consists of millions of TINY particles of diverse chemical composition. Particulate matter from tobacco smoke includes many particles in the size range that REFLECTS light, which explains why tobacco smoke is easily seen by the eye. In contrast to smoke particles, gases emitted by the cigarette such as benzene and carbon monoxide (CO) are invisible to the eye. Particles smaller than 2.5 micrometers (PM2.5) are major components of cigarette smoke and can enter deep into the lung where they can cause serious health problems. The pollutants generated by the cigarette arise from the chemical process of burning organic matter, or combustion of tobacco and paper. Combustion processes, such as WOOD burning or waste incineration, emit thousands of pollutants, some of which are in the gas PHASE and some of which are in the form of SMALL particles called particulate matter.

 Homogeneous SYSTEMS

An alloy is a mixture or METALLIC solid solution composed of two or more elements. So they are heterogeneous systems. Complete solid solution alloys GIVE single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal (heat treatment) history. Alloys USUALLY have different properties from those of the component elements.

 CARBONYL CHLORIDE

Tear GAS is Carbonyl chloride.

 Aqua REGIA

Aqua regia is a mixture of concentrated hydrochloric acid and NITRIC acid in the ratio of 3:1, and can DISSOLVE noble metals LIKE gold.

 Distilled WATER

Water (H₂O) is the most abundant compound on EARTH's SURFACE. Water is a compound because it contains oxygen and hydrogen which are chemically COMBINED in proportion.

 Paraffin was and STEARIC acid

Most candles are made from paraffin wax, a byproduct of petroleum refining. Candles can ALSO be made from microcrystalline wax, beeswax (a byproduct of honey collection), gel (a mixture of polymer and mineral oil), or some plant WAXES (generally PALM, CARNAUBA, bayberry, or soybean wax).

 MOLTEN ZINC

'Brass' is a SOLUTION of molten COPPER in Molten zinc. Brass is an ALLOY of 'copper and zinc'.

 Solid dispersed in gas

Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires (including stoves, candles, oil lamps, and fireplaces), but may ALSO be used for pest control (cf. fumigation), communication (smoke signals), defensive and offensive capabilities in the military (smokescreen), COOKING (smoked salmon), or smoking (tobacco, CANNABIS, etc.). Smoke inhalation is the primary cause of death in victims of indoor fires. The smoke kills by a COMBINATION of thermal damage, poisoning and pulmonary irritation caused by carbon MONOXIDE, hydrogen cyanide and other combustion products.

 HYDROGEN

The LIGHTEST chemical ELEMENT is Hydrogen and the heaviest is HASSIUM.

 MICA

Sheet mica is used PRINCIPALLY in the electronic and electrical INDUSTRIES. Its usefulness in these applications is derived from its unique electrical and thermal insulating properties and its mechanical properties, which allow it to be cut, punched, stamped, and MACHINED to CLOSE tolerances. Specifically, Mica is unusual in that it is a good electrical insulator at the same time as being a good thermal conductor.

 H₂SO₄

The major use of sulphur is in the MANUFACTURE of sulphuric ACID (H₂SO₄) which is one of the most important compounds made by the chemical industry. It is USED to make, literally, hundreds of compounds needed by almost every industry.

 REMAINS same

Generally, DILUTION has no EFFECT on the PH.

 All of the above

Sulphur dioxide PRESENT in the industrial CHIMNEY exhaust causes respiratory and lung disease REDUCTION in PLANT's productivity owing to acid rain and corrosion BUILDING materials.

 Thorium

Monazite is an important ore for thorium, lanthanum, and cerium. It is often found in PLACER deposits. INDIA, Madagascar, and SOUTH AFRICA have large deposits of monazite sands. The deposits in India are particularly RICH in monazite.

 Cement

Limestone is USED as a raw-material for the manufacture of quicklime (calcium oxide), slaked lime (calcium hydroxide), cement and MORTAR. CLAY and shale are also used as raw MATERIALS for the PRODUCTION of cement.

 Copper at CATHODE and OXYGEN at anode

Electrolysis of an aqueous solution of copper sulphate USING copper ELECTRODES gives copper at cathode and oxygen at anode.

 Formation of lather with SOAP

Soap solution is used to measure the HARDNESS of rain water, temporarily hard water and sea-water. Hard water does not form soap lather. This is because magnesium ions or calcium ions PRESENT in hard water react with soap to form calcium stearate or magnesium stearate and thus FORMS scum.

 Acetylsalicylic acid

One of the best KNOWN aromatic acetates is acetylsalicylic acid, or aspirin, which is prepared by the esterification of the PHENOLIC HYDROXYL group of salicylic acid. Aspirin possesses a number of properties that make it the most often RECOMMENDED DRUG.

 6.02310²³

Number of 6.023 × 10²³ ATOMS present in one MOLE of a GAS at STP is 6.023 × 10²³.

 Butane

Butanes are highly flammable, colourless, EASILY LIQUEFIED gases. When blended with propane and other hydrocarbons, it is REFERRED to commercially as LPG, for liquefied PETROLEUM gas.

 Helium

A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon FABRIC, while some early balloons were made of dried animal bladders, such as the pig bladder. Some balloons are used for decorative PURPOSES, while others are used for practical purposes such as meteorology, MEDICAL treatment, military defense, or transportation. A balloon’s PROPERTIES, including its low density and low cost, have LED to a wide range of applications. Because of the non combustible property of the helium gas it is widely used in weather balloons rather than hydrogen gas which is highly combustible.

 presence of free electrons

Metallic LUSTRE is due to the mobile electrons PRESENT in METALS which when de-excites releases ENERGY in the form of light.

 HIGH CONCENTRATION of SALT

Saline SOIL CONTAINS high concentration of salt.

 DETERGENT

Hard WATER and SOFT water can be DISTINGUISHED by USING detergent.

 Tetraethyl LEAD

An anti-knocking agent is the substance which is used to reduce the engine knocking. It increases the OCTANE number of the fuel. It helps in auto-ignition by raising the TEMPERATURE and pressure. TEL is tetraethyl Lead which is used as an anti-knocking compound.

 Reflection of light due to the presence of free electrons

Lustre (or luster) is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the latin lux, meaning “light”, and generally implies radiance, gloss, or brilliance. Metals in general have high electrical conductivity, high thermal conductivity, and high density. Typically they are malleable and ductile, deforming under stress without cleaving. In terms of optical properties, metals are shiny and lustrous. Sheets of METAL beyond a few micrometres in THICKNESS appear opaque, but gold leaf transmits GREEN light. Metallic (or splendant) minerals have the lustre of polished metal, and with ideal surfaces will work as a reflective surface. Examples INCLUDE galena, pyrite and magnetite.

 LEWIS ACID

Aluminium CHLORIDE is Lewis acid.

 HELIUM is less DENSE than air

In the BEGINNING the balloon filled with helium rieses in air because weight of the air displaced by balloon is more than the weight of the balloon and helium GAS filled inside balloon. We know that the density of air and the value of acceleration due to gravity decreases with height.

 Nitrogen

Nitrogen is CHEMICALLY unreactive because it has a strong triple bond which binds the two nitrogen atoms together making it harder for it to be broken. It does not burn, and at ORDINARY temperatures it does not REACT with other ELEMENTS.

 Dalton

John Dalton (1766-1844) DEVELOPED the FIRST useful ATOMIC THEORY of matter.

 Furan

The most common HETEROCYCLES are those having five- or six-membered rings and containing heteroatoms of NITROGEN (N), OXYGEN (O), or sulfur (S). The BEST known of the simple heterocyclic compounds are pyridine, pyrrole, furan, and thiophene.

 6-7

A FERTILE SOIL is LIKELY to have a PH of 6-7.

 LUMINOUS zone

The HOTTEST part of the GAS FLAME is known as luminous zone.