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 Decomposition of manganese dioxide

One of the two CHEMICAL methods starts from NATURAL manganese dioxide and converts it USING dinitrogen tetroxide and water to manganese nitrate solution. Evaporation of the water LEAVES the crystalline nitrate SALT. At temperatures of 400°C, the salt decomposes, releasing N2O4 and leaving a residue of purified manganese dioxide.

 Surface tension

Detergents and soaps are used for cleaning because pure water can’t remove oily, organic soiling. Soap cleans by acting as an emulsifier. Basically, soap allows oil and water to mix so that oily grime can be removed during rinsing. Detergents were developed in response to the shortage of the animal and vegetable fats used to make soap during World War I and World War II. Detergents are primarily surfactants, which could be produced easily from petrochemicals. Surfactants lower the surface tension of water, essentially making it ‘wetter’ so that it is less likely to stick to itself and more likely to interact with oil and grease. Modern detergents contain more than surfactants. Cleaning products may ALSO contain enzymes to DEGRADE protein-based stains, bleaches to de-colour stains and add power to cleaning agents, and BLUE dyes to counter yellowing. Like soaps, detergents have hydrophobic or water-hating molecular chains and HYDROPHILIC or water-loving components

 ZINC OXIDE

Philosopher’s WOOL is Zinc oxide.

 Zinc

Galvanisation or GALVANIZATION (or GALVANIZING as it is most commonly called) is the process of applying a protective zinc coating to IRON or steel, to prevent RUSTING.

 METHYL isocyanate

3 leak of toxic methyl isocyanate GAS at a Union CARBIDE plant in the central Indian city of Bhopal produced history's worst industrial disaster, STUNNING India and the WORLD.

 HYDRATION and dissociation of water

Cements (e.g., Portland cement) harden because of hydration, chemical REACTIONS that occur independently of the mixture’s water content; they can harden even underwater or when constantly EXPOSED to wet weather. The chemical reaction that results when the anhydrous cement POWDER is mixed with water produces hydrates that are not watersoluble.

 BROMINE

The only LIQUID ELEMENTS at standard temperature and pressure are bromine (Br) and MERCURY (Hg).

 Calcium oxalate

The most common TYPE of kidney stone is a calcium oxalate stone. These result when the urine contains low levels of citrate and high levels of calcium and either oxalate or URIC acid. Calcium oxalate STONES are LINKED with foods high in oxalate, which is a NATURALLY occurring substance in plants and animals.

 Mg

In the US, 63% of MAGNESIUM production came from seawater and brines during 2015. The METAL is extracted from seawater and brines by MEANS of electrolysis, a process that requires the passing of a current through a MOLTEN salt.

 Carbon DIOXIDE

The acidity of rainwater comes from the natural presence of three substances (CO₂, NO, and SO₂) FOUND in the troposphere (the lowest layer of the atmosphere). As is seen in Table I, carbon dioxide (CO₂) is present in the greatest concentration and therefore CONTRIBUTES the most to the natural acidity of rainwater.

 Mortar

Mortar is a workable paste USED to bind BUILDING BLOCKS such as bricks units to fill and seal the GAPS. It is a mix of sand, a binder and water.

 CHLOROXYLENOL + terepineol

Commonly USED ANTISEPTIC, DETTOL is a MIXTURE of chloroxylenol and terpineol.

 Water

Since water and carbon dioxide are both compounds which contain oxygen, it is possible to obtain oxygen from either. The oxygen produced from photosynthesis is not released into the air. It is not until CELLULAR respiration that oxygen is released. The oxygen comes from water. The water molecules are split at the “BEGINNING” of photosynthesis for the electrons. These electrons eventually make their way to the electron transport chain, where oxygen is the final electron ACCEPT, and then released into the air. SCIENTISTS agree that there’s oxygen from ocean plants in every breath we take. Most of this oxygen comes from tiny ocean plants – called PHYTOPLANKTON – that live near the water’s surface and drift with the currents. Like all plants, they photosynthesize – that is, they use sunlight and carbon dioxide to make food. A byproduct of photosynthesis is oxygen.

 Methane

Naturally occurring mixture of a HYDROCARBON gas with methane being the PRIMARY constituent is CALLED natural gas. Other gases found in MINUTE traces are hydrogen, hydrogen sulphide, nitrogen, carbon monoxide and carbon dioxide.

 Gold

There are many pure FORMS of CARBON in EARTH, but Diamond is the purest FORM of carbon. Other pure forms are graphite, fullerene and CHARCOAL. Gold is not a form of carbon.

 Silicon

Because of its unique internal ATOMIC structure and its ready availability, silicon is WIDELY used for solar cells. One of the elements of the PERIODIC Table of the Elements, silicon is known as a semiconductor, a substance that conducts electricity when there is a CHANGE to its environment.

 Insulin

Insulin is an antidiabatic DRUG.

 PUNE

National Chemical LABORATORY (CSIR-NCL), Pune, established in 1950, is a CONSTITUENT laboratory of Council of Scientific and Industrial RESEARCH (CSIR).

 3

Covalency is the number of covalent BOND of an element or COMPOUNDS. So nitrogen have 3 covalent bond and 1 co ordinate bond. So covalency of nitrogen is 3.

 1.0 mg/m³

The THRESHOLD LIMIT VALUE (TLV) of copper in ATMOSPHERIC air is 1.0 mg/m³.

 GRAPHITE

Graphite is not a MIXTURE. This is because graphite is a pure element which cannot SPLIT into its CONSTITUENT particles.

 3.05 gram

Balanced chemical EQUATION:
P₄ + 5O₂ --------> P₄O₁₀
1 mol 5 mol 1 mol
124g 160g 284g
Here limiting REAGENT is P₄.
So, 124g of P₄ produce P₄O₁₀ = 284g
Therefore,
1.33g of P₄ produce P₄O₁₀ = (284/124)*1.33
= 3.05g

 Becomes more strong

In cement almost entire amount of lime is present in COMBINED STATE as CALCIUM silicates and calcium aluminates. Cement containing EXCESS amount of lime cracks during setting while cement containing less amount of lime is weak in strength. Setting of cement is an EXOTHERMIC process.

 Helium

Helium is an EXAMPLE of NOBLE GAS.

 diamond

The allotropes of CARBON include graphite, ONE of the softest KNOWN substances, and diamond, the hardest naturally OCCURRING substance.

 Bohr and RUTHERFORD

Bohr and Rutherford developed the MODEL of ATOMIC STRUCTURE.

 19

An atom of an ELEMENT has atomic number 17 and MASS number 36. The number of NEUTRONS in its nucleus is 19.

 Flourine

Flourine is the most REACTIVE GASEOUS ELEMENT.

 METHYL ALCOHOL and H₂O

Methyl alcohol and WATER are used as an anti-freeze in RADIATORS of automobiles.

 78.03

The air in Earth's atmosphere is made up of APPROXIMATELY 78 percent NITROGEN and 21 percent oxygen. Air also has small amounts of LOTS of other gases, too, such as carbon dioxide, neon, and HYDROGEN.

 Xenon

Xenon can FORM COMPOUNDS.

 LD₅₀

LD stands for "Lethal Dose". LD50 is the AMOUNT of a MATERIAL, given all at once, which causes the death of 50% (one half) of a GROUP of test animals. The LD50 is one WAY to measure the short-term poisoning potential (acute toxicity) of a material.

 Carbon

A smoke bomb is a firework designed to produce smoke UPON ignition. Smoke bombs are useful to military units, airsoft games, paintball games, selfdefense and pranks. The smoke bomb was first created in 1848, by the INVENTOR Robert Yale. He developed 17th century Chinese-style fireworks and later modified the formula to produce more smoke for a longer PERIOD of time. Coloured smoke devices use a formula that consists of an oxidizer (typically potassium chlorate, KClO₃), a fuel (GENERALLY sugar), a moderant (such as sodium bicarbonate) to KEEP the reaction from getting too hot, and a powdered organic dye. The burning of this mixture evaporates the dye and forces it out of the device, where it condenses in the atmosphere to form a “smoke” of finely dispersed particles. A smoke ball is a hollow, cherry-sized sphere of brightly coloured clay or cardboard filled with a smoke-generating composition that produces a forceful jet of coloured smoke for 10 to 15 seconds.

 Unsaturation in OIL

Iodine value can be USED to measure the degree of unsaturation of oils and fats. The RESULTS are normally expressed as the NUMBER of grams of iodine absorbed by 100 G of oil or fat, considering the conditions of the test.

 D-block

Copper (Cu) has the ATOMIC number of 29. Copper belongs to the d-block which is the collective name for GROUPS 3 to 12 in the periodic table. Most of the d-block elements are considered to be metals, with a COMMON lustrous metallic appearance.

 ACETOPHENONE

The FORMULA C₆H₅-CO-CH₃ REPRESENTS Acetophenone.

 Silicon and Germanium

A transistor is a semiconductor device used to amplify and switch electronic signals and electrical POWER. Semiconductor material (date first used): the metalloids germanium (1947) and silicon (1954) — in amorphous, polycrystalline and mono-crystalline form; the compounds gallium ARSENIDE (1966) and silicon carbide (1997), the alloy silicon-germanium (1989), the allotrope of carbon graphene (research ongoing since 2004), etc.

 NONPOLAR

Ethylene is a nonpolar MOLECULE.

 Melamine

Melamine FORMALDEHYDE RESIN is the POLYMER used for making plastic crockery. Its MONOMERS are melamine and formaldehyde. Uses : It is used in making plastic (UNBREAKABLE) crockery.

 Calcium carbide

Pouches of calcium carbide are placed with mangoes. When this chemical comes in CONTACT with moisture, acetylene gas is produced, the EFFECTS of which are similar to ethylene, the one that is naturally USED for fruit RIPENING process.

 Caffeine

Caffeine (C₈H₁₀N₄O₂) is a bitter alkaloid found especially in coffee, TEA, CACAO, and KOLA nuts.

 Carbon dioxide

Carbon dioxide (CO₂) is the PRIMARY GREENHOUSE gas emitted through HUMAN activities.

 CHROMIUM

Chromium is mainly found in waste from the CHROME tanning process; it occurs as part of the retanning system and is displaced from leathers during retanning and dyeing processes. This chrome is discharged from processes in soluble form; however, when mixed with tannery waste waters from other processes (ESPECIALLY if PROTEINS are present), the reaction is very rapid. Precipitates are formed, mainly protein-chrome, which add to sludge generation. If chrome discharges are excessive, the chromium might remain in the solution. Even in low concentrations, it has a toxic effect upon DAPHNIA, thus disrupting the food chain for fish life and possibly inhibiting photosynthesis.

 ADSORPTION

Activated CHARCOAL is used to remove COLOURING matter from pure substances. It works by adsorption. COLOUR impurities are adsorbed on the SURFACE of activated charcoal.

 Teflon

The modern non-stick PANS were MADE using a coating of Teflon (polytetrafluoroethylene or PTFE). PTFE was invented serendipitously by ROY Plunkett in 1938, while working for a JOINT venture of the DuPont COMPANY.

 Activation energy

The minimum AMOUNT of energy that MOLECULES MUST have in order for a reaction to occur upon collision is called activation energy.

 80

The ATOMIC NUMBER of MERCURY is 80.

 Cooking

LPG is Liquefied Petroleum Gas and PNG is Piped Natural Gas. LPG is supplied in LIQUID FORM just as the NAME suggests in cylinders whereas PNG is supplied through a PIPELINE. LPG is USED as a fuel in heating appliances and vehicles, where as PNG is used for cooking (gas stoves) and heating water (gas geysers).

 Calcium silicate and calcium aluminate

Portland cement is the most common type of cement in general use around the world because it is a basic INGREDIENT of concrete, mortar, stucco and most nonspecialty grout. It usually originates from LIMESTONE. It is a fine powder produced by grinding Portland cement clinker (more than 90%), a limited amount of calcium sulfate (which controls the set TIME) and up to 5% minor constituents. Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates, the remainder consisting of aluminium- and iron-containing clinker PHASES and other compounds.

 “3 to +5

Nitrogen FORMS a VARIETY of COMPOUNDS in all oxidation STATES RANGING from –3 to +5.