1240+ Chemistry Solved MCQs

501.

Sour taste of lemon is due to the presence of which of the follow-ing?

A. Citric acid
B. Acetic acid
C. Oxalic acid
D. Formic acid
Answer» A. Citric acid
Explanation: Lemon juice is about 5% citric acid, which gives lemons a sour taste and a pH of 2 to 3. Citric acid is found in many fruits but lemon contains large quantity of citric acid. The distinctive sour taste of lemon juice makes it a key ingredient in drinks and foods such as lemonade and lemon meringue pie.
502.

Ethylene is a molecule.

A. polar
B. ionic
C. covalent
D. nonpolar
Answer» D. nonpolar
Explanation: Ethylene (C2H4) is a nonpolar molecule. This is because, unlike a polar molecule, it has an even distribution of electrical charges. Since, the double bond is between two carbon atoms, there is no difference in the electro negativity. This is why, the shared pair of electrons come lie in between those to carbon atoms. As a result, ethylene is a non-polar and linear molecule.
503.

If water smells bad, then that odour can be removed by adding –

A. alum
B. bleach
C. activated carbon
D. deactivated nitrogen
Answer» C. activated carbon
Explanation: Adding powdered activated carbon to water or using of granular activated carbon (GAC) in the water filter can remove bad taste and foul odour. Powdered activated carbon (PAC) is the preferred method when the taste and odour is moderate and infrequent. Activated carbon works by a phenomenon called "Adsorption", which is where the odour compound is trapped inside the activated carbon and retained, but the material doing the adsorption does not change size.
504.

The basic process taking place in nuclear reactors is -

A. Radioactivity
B. Fission
C. Fusion
D. None of the above
Answer» B. Fission
Explanation: A nuclear reactor produces and controls the re-lease of energy from splitting the atoms of uranium, known as nuclear fission. When a fissile atomic nucleus such as uranium- 235 or plutonium-239 absorbs a neutron, it undergoes nuclear fission in which the heavynucleus splits into two or more lighter nuclei. The fission process produces free neutrons and gamma pho-tons, and releases a very large amount of energy.
505.

Malathion is a/an -

A. insecticide
B. fumigant
C. preservative
D. pesticide
Answer» A. insecticide
Explanation: Malathion is an organophosphate (OP) insecticide that has been registered for use in the United States since 1956. It is widely used in agriculture, residential landscaping, public recreation areas, and in public health pest control programs such as mosquito eradication. It is of relatively low human toxicity.
506.

Glycol is used to manufacture which of the following?

A. Nylon
B. Artificial silk
C. Terylene
D. Rubber
Answer» C. Terylene
Explanation: Monoethylene glycol (MEG), also known as ethylene glycol (EG) or simply glycol, is a diol mostly used for the production of polyester fibers and polyethylene terephthalate (PET) resins. Polyethylene terephthalate is used to produce textiles, large soft-drink containers, photographic film, and overhead transparencies.
507.

During fermentation of sugar, the compound which is always formed is –

A. Methyl Alcohol
B. Ethyl Alcohol
C. Acetic Acid
D. Ethylene
Answer» B. Ethyl Alcohol
Explanation: Fermentation is the conversion of sugar into car-bon dioxide has (CO2) and ethyl alcohol. This process is carried out by yeast cells using a range of enzymes.
508.

Warming Ammonium chloride with sodium hydrochloride in a test tube is an example of –

A. Open system
B. Closed system
C. Isobaric system
D. Isothermal system
Answer» A. Open system
Explanation: When heated, ammonlinm chloride decomposes into ammonia and hydrogen chloride. The thermal decomposition of ammonium chloride is a reversible chemical change. On heating above 340°C, it decomposes to form two gases such as ammonia and hydrogen chloride. On cooling, the reaction is reversed and solid ammonium chloride is formed.
509.

Laughing gas is –

A. Nitric oxide
B. Nitrous oxide
C. Nitrogen trioxide
D. Nitrogen pentoxide
Answer» B. Nitrous oxide
Explanation: Laughing gas is Nitrous Oxide (N2O).
510.

Calcium salts used as fertilizer is –

A. Calcium Carbide
B. Calcium Carbonate
C. Calcium Cyanide
D. Calcium Sulphate
Answer» D. Calcium Sulphate
Explanation: Sulphur (as sulphate) is a major plant nutrient, and is essential for crop growth. Calcium Sulphate (gypsum) is used to improve soil quality. Calcium sulphate acts as a pH buffer, which can contribute to neutralizing both soil alkalinity and acidity. It is mainly used for the reclamation of sodic soils through ion exchange (calcium replacing sodium).
511.

Which one of the following has a maximum tendency to form M^3 ion?

A. N
B. Bi
C. P
D. As
Answer» A. N
Explanation: Thee general electronic configuration of group 15 elements (N, P, As, Sb and Bi) is ns2np3. Since Nitrogen has smallest size and greatest electronegativity in the family, it may gain three electrons and attain noble has configuration, forming nitride N3- ions.
512.

Copper substances when exposed to air gains a green coating due to the formation of:

A. CuO
B. CuCO3 Cu(OH)2
C. CuSO4
D. Cu(NO3)2
Answer» B. CuCO3 Cu(OH)2
Explanation: When copper is exposed to air, it reacts with moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat. This green substance is basic copper carbonate (CuCO3 Cu(OH)2). The formation of this green coating on the surface of a copper object corrodes it.
513.

Bagasse, a by-product of sugar manufacturing industry, is used for the production of -

A. Glass
B. Paper
C. Rubber
D. Cement
Answer» B. Paper
Explanation: 0
514.

Bleaching powder is made from -

A. Sulphur dioxide and gypsum
B. Chlorine and Charcoal
C. Soda ash and lime
D. Lime and Chlorine
Answer» D. Lime and Chlorine
Explanation: The gas which is used in the preparation of bleaching powder is chlorine. It is a mixture of lime and calcium chloride.
515.

Which one of the following does not contain silver?

A. Horn silver
B. Ruby silver
C. German silver
D. Lunar caustic
Answer» C. German silver
Explanation: 0
516.

An important green-house gas other than methane being produced from the agricultural fields is–

A. Nitrous oxide
B. Ammonia
C. Sulphur dioxide
D. Arsine
Answer» A. Nitrous oxide
Explanation: Nitrous oxide (N2O) and methane (CH4) are the two major greenhouse gasses (GHG) emitted by agricultural activities. N2O accounts for around 8% of the warming impact of current human GHG emissions.
517.

Which one of the following contains maximum percentage of carbon?

A. Cast iron
B. Stainless steel
C. Wrought iron
D. High speed steel
Answer» A. Cast iron
Explanation: Cast Iron is a hard, brittle, nonmalleable iron-carbon alloy, cast into shape, containing 2 to 4.5 percent carbon. Steels contain less than 2% and usually less than 1% carbon, while all cast irons contain more than 2% carbon. Most steel contains less than 0.35 percent carbon. Wrought iron is an iron alloy with very low carbon (0.04 to 0.08%) content.
518.

Whichof the following appeared to be with a significant potential for accumulation through food chains?

A. DDT
B. Parathion
C. Lindane
D. Carbary
Answer» A. DDT
Explanation: Mercury and DDT are two persistent toxic materials that accumulate in the food chain and damage the organisms in it. DDT is an insecticide that can pass up the food chain from insects to small birds, and then from the small birds to birds of prey. It is now banned because of this.
519.

The moderator used in a nuclear reactor is –

A. Uranium
B. Radium
C. Ordinary water
D. Graphite
Answer» C. Ordinary water
Explanation: Light water (ordinary water) is used as the moderator in U.S. reactors as well as the cooling agent. It acts as the means by which heat is removed to produce steam for turning the turbines of the electric generators.
520.

Which among the following is a carbohydrate?

A. Nylon
B. Cane-sugar
C. Turpentine
D. Hydrogen peroxide
Answer» B. Cane-sugar
Explanation: Cane-sugar is carbohydrate and as this name implies, is composed of carbon, hydrogen and oxygen. it is a source of extracting sugar. There are various types of sugar derived from different sources. Simple sugars are called monosaccharides and include glucose, fructose and galactose. The table or granulated sugar most customarily used as food is sucrose, a disaccharide. Other disaccharides include maltose and lactose.
521.

Which among the following metals provides amphoteric oxide?

A. Sodium
B. Silver
C. Aluminium
D. Calcium
Answer» C. Aluminium
Explanation: In chemistry, an amphoteric
522.

Iodine can be separated from a mixture of Iodine and Potassium Chloride by –

A. sedimentation
B. filtration
C. sublimation
D. distillation
Answer» C. sublimation
Explanation: Iodine is well known to sublime (change from solid to gas without becoming liquid in between) when heated. However sodium chloride has a melting point much higher than that of iodine. Therefore, a mixture of iodine and sodium chloride can be separated by using a sublimation apparatus, with solid iodine collected by condensation on a cold surface.
523.

Identify the metal which is non toxic in nature.

A. Chromium
B. Gold
C. Cadmium
D. Cobalt
Answer» B. Gold
Explanation: Toxic metals are metals that form poisonous soluble compounds and have no biological role, i.e. are not essential minerals, or are in the wrong form. Most often the definition includes at least cadmium, lead, mercury and the radioactive metals. Metals in an oxidation state abnormal to the body may also become toxic: chromium (III) is an essential trace element, but chromium (VI) is a carcinogen. Similarly, cobalt could also be toxic.
524.

Bakelite is a copolymer of Phenol and -

A. Formaldehyde
B. Acetaldehyde
C. Benzaldehyde
D. Cinnaldehyde
Answer» A. Formaldehyde
Explanation: Bakelite is an early plastic. It is a thermosetting phenol formaldehyde resin, formed from an elimination reaction of phenol with formaldehyde.
525.

What is a mixture of potassium nitrate powdered charcoal and sulphur called?

A. paint
B. aluminium
C. brass
D. gun powder
Answer» D. gun powder
Explanation: Gun powder is the mixture of potassium nitrate powdered charcoal and sulphur.
526.

Which among the following metal is used for galvanization?

A. Zinc
B. Copper
C. Iron
D. Silver
Answer» A. Zinc
Explanation: Galvanization is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which parts are submerged in a bath of molten zinc.
527.

The lightest radioactive element is -

A. deuterium
B. polonium
C. technetium
D. uranium
Answer» C. technetium
Explanation: Tritium is a radioactive isotope of hydrogen. It is the lightest radioactive element.
528.

The chemical used in developing photographic films is –

A. silver bromide
B. hypo
C. sodium sulphate
D. hydroquinone
Answer» A. silver bromide
Explanation: Tritium is a radioactive isotope of hydrogen. It is the lightest radioactive element.
529.

Hard water and soft water can be distinguished by using –

A. dilute acid
B. ordinary soap
C. detergent
D. liquid soap
Answer» C. detergent
Explanation: 0
530.

Gamma rays are -

A. High energy electrons
B. Low energy electrons
C. High energy electromagnetic
D. High energy positron waves
Answer» C. High energy electromagnetic
Explanation: Gamma rays (γ) refer to electromagnetic radiation of an extremely high frequency and therefore consist of high energy photons.
531.

The name of unreactive gas is –

A. Carbon dioxide
B. Hydrogen
C. Nitrogen
D. Oxygen
Answer» C. Nitrogen
Explanation: 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.
532.

Heavy water is so called because it contains -

A. Heavy isotope of hydrogen
B. Heavy isotope of oxygen
C. Mole number of hydrogen atoms
D. Mole number of oxygen atoms
Answer» A. Heavy isotope of hydrogen
Explanation: Heavy water, formally called deuterium oxide, is a form of "water that contains a larger than normal amount of the hydrogen isotope deuterium, (also known as "heavy hydrogen") rather than the common hydrogen-1 isotope that makes up most of the hydrogen in normal water.
533.

Heating of a ore below its melting point in the absence of air is known as –

A. Refining
B. Calcination
C. Roasting
D. Smelting
Answer» B. Calcination
Explanation: Calcination involves simple decomposition of ore on heating below its melting point usually in absence of air to produce new compounds having higher percentage of metal as well as removing the moisture, organic matter and volatile impurities. Calcination makes the ore porous.
534.

The most electronegative element among the following is –

A. Fluorine
B. Sodium
C. Chlorine
D. Oxygen
Answer» A. Fluorine
Explanation: Electronegativity of the elements using the Pooling Scale is as follows: Fluorine: 3.98, Oxygen: 3.44, Chlorine: 3.16, and Sodium: 0.93. Electronegativity increases down the group and decreases down the period.
535.

The quality of petrol is expressed in terms of –

A. Cetane number
B. Gold number
C. Octane number
D. Added unlead compounds
Answer» C. Octane number
Explanation: Octane rating or octane number is a standard measure of the of the ignition quality of has (gasoline or petrol). Higher this number, the less susceptible is the gas to `knocking' (explosion caused by its premature burning in the combustioncharnber) when burnt in a standard (spark-ignition internal combustion) engine.
536.

The percentage of Nitrogen in Air is -

A. 0.94
B. 0.03
C. 78.03
D. 85.02
Answer» C. 78.03
Explanation: By volume, thy air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%.
537.

Energy is continuously generated in the sun due to               .

A. Nuclear fusion
B. Nuclear fission
C. Radioactivity
D. Artificial radioactivity
Answer» A. Nuclear fusion
Explanation: Nuclear fusion is a nuclear reaction in which two or more atomic nuclei come very close and then collide at a very high speed and join to form a new type of atomic nucleus.
538.

The apparatus used to test acidity of aqueous solution is -

A. pH meter
B. Ammeter
C. Hygrometer
D. Acidmeter
Answer» A. pH meter
Explanation: A pH meter is an electronic device used for measuring the pH (acidity or alkalinity) of a liquid. A typical pH meter consists of a special measuring probe (a glass electrode) connected to an electronic meter that measures and displays the pH reading.
539.

Chemical formula of washing soda is -

A. Na2SO4.10H2O
B. NaHCO3
C. Na2CO3.10H2O
D. Ca(OH)2
Answer» C. Na2CO3.10H2O
Explanation: Washing Soda is essentially Sodium Carbonate, a sodium salt of carbonic acid (soluble in water). The molecular formula of washing soda is Na2CO3.10H2O. It is used as an agent to soften hard water. It reacts with the calcium and magnesium bonds present in the water, enabling the detergent to work.
540.

Which one of the following elements is an example of noble gas?

A. Nitrogen
B. Hydrogen
C. Chlorine
D. Helium
Answer» D. Helium
Explanation: Noble gas refers to any of the seven chemical elements that make up Group Villa of the periodic table. The elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and element 118 (temporarily named ununoctium [Uuo]).
541.

Which of the following elements does not exhibit natural radioactivity?

A. Uranium
B. Thorium
C. Aluminium
D. Polonium
Answer» C. Aluminium
Explanation: Uranium, Thorium and Polonium are radioactive elements which do not have stable naturally occur-ring isotope. Aluminium is a silvery white, soft, ductile metal. It is the third most abundant element (after oxygen and silicon), and the most abundant metal in the Earth's crust.
542.

Which of the following chemicals is responsible for depletion of ozone layer in the atmosphere?

A. Chlorofluorocarbons
B. Nitrous oxide
C. Sulphur dioxide
D. Carbon dioxide
Answer» A. Chlorofluorocarbons
Explanation: Chlorofluorocarbon contributes to ozone depletion in the upper atmosphere. It is an organic compound that contains only carbon, chlorine, and fluorine, produced as a volatile derivative of methane, ethane, propane. Its manufacture has been phased out under the Montreal Protocol.
543.

In which of the following states maximum iron ore is found?

A. FeCO₃
B. Fe₂O₃
C. Fe₃O₄
D. FeS₂
Answer» B. Fe₂O₃
Explanation: Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in colour from dark grey, bright yellow, or deep purple to rusty red.
544.

The deterioration of a metal by an electrochemical process is commonly termed as –

A. Erosion
B. Corrosion
C. Passivation
D. Abrasion
Answer» B. Corrosion
Explanation: Corrosion can be defined as the deterioration of materials by chemical processes.
545.

The chief constituent of natural gas is:

A. Methane
B. Helium
C. Nitrogen
D. Propalie
Answer» A. Methane
Explanation: Natural gas is a naturally occurring hydrocarbon has mixture consisting primarily of methane (CH4). However, it also includes varying amounts of other higher alkanes (ethane, propane), and a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or helium.
546.

The source of energy that causes the least global warming is –

A. Coal
B. Geothermal energy
C. Natural Gas
D. Petroleum
Answer» C. Natural Gas
Explanation: Fossil fuels — coal, petroleum, and natural gas — are the primary culprit behind climate change. They contribute more than 80 percent of greenhouse gas emissions — and 98 percent of CO2 emissions alone. On the contrary, Geothermal energy is thermal energy generated and stored in the Earth. It is clean and sustainable.
547.

Which of the following is not a donor atom?

A. Phosphorus
B. Antimony
C. Arsenic
D. Aluminium
Answer» D. Aluminium
Explanation: Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged. In semiconductor physics. It is a dopant atom that when added to a semiconductor can form a p- type region.
548.

Formic acid is produced by –

A. White ants
B. Cockroaches
C. Red ants
D. Mosquitoes
Answer» C. Red ants
Explanation: Formic acid (HCO2H) occurs naturally, most notably in some ants. The word "formic" comes from the Latin word for ant, formica, referring to its early isolation by the distillation of ant bodies. It is this compound that causes most of the irritation that occurs immediately following an ant bite or a bee sting.
549.

Which one of the following forms of phosphorus is most reactive?

A. Black phosphorus
B. White phosphorus
C. Violet phosphorus
D. Red phosphorus
Answer» B. White phosphorus
Explanation: White phosphorus is the most reactive form of phosphorus. It is made up of discrete P4 tetrahedra which are subjected to very high angular strain as the angles is 60 degrees. This high angular strain makes white phosphorus unstable and highly reactive. It ignites spontaneously at about 50°C, and at much lower temperatures if finely divided.
550.

Rcmoval of carbon particles from air involves the principle of –

A. Precipitation
B. FiIteration
C. Electrophoresis
D. Sedimentation
Answer» C. Electrophoresis
Explanation: Carbon particles in air are colloidal in nature and carry negative charge. The removal of carbon parities from air involves the principle of electrophoresis. Carbon particles get precipitated by losing their charge and, thus, the air which finally comes out is free from them.
551.

Which of the following acts as best adsorbent?

A. Charcoal
B. Activated Charcoal
C. Activated Coconut Charcoal
D. Carbon black
Answer» C. Activated Coconut Charcoal
Explanation: Activated coconut charcoal is a highly absorbent material with millions of tiny pores that can capture, bind, and remove unwanted materials. The porous surface has a negative electric charge that attracts positively charged toxins and gas to be carried easily out of the body. It is used medicinally as well as in air and water purifiers.
552.

Which of the following is used as no coating for Cooking utensils?

A. Perspex
B. Styrofoam
C. Polystyrene
D. (4)Teflon
Answer» D. (4)Teflon
Explanation: The non-stick coating used mainly for coating cooking utensils is made using PTFE (polytetrafluoroethylene) that is also known by the name Teflon. Teflon is an inert polymer with high thermal and chemical resistance. Besides, it is hydrophobic: neitherwater nor water-containing substances wet it and it has one of the lowest coefficients of friction of any solid.
553.

The least preferred technique in the disposal of Municipal Solid Waste is -

A. Incineration
B. Composting
C. Land filling
D. Bricketting
Answer» D. Bricketting
Explanation: Some of the methods of solid waste disposal and management are :
Open burning Dumping into the sea Sanitary Landfills Incineration Composting Ploughing in fields Hog feeding
Grinding and discharging into sewers Salvaging
Fermentation and biological digestion
Bricketting that involves the solidification of preprocessed municipal solid waste into fuel pellets or briquettes is the least preferred method of solid waste disposal.
554.

Which is the heaviest metal among the following?

A. Gold
B. Silver
C. Iron
D. Copper
Answer» A. Gold
Explanation: The heaviness of any metal is defined with reference to high densities, atomic weights, or atomic numbers. The atomic masses of the given elements are: Gold: 196.96654; Silver: 107.8682; Copper: 63.546; Iron: 55.847. So the heaviest metal is gold, followed by silver, copper and iron.
555.

Which of the following is a commercial source of energy?

A. Agricultural waste
B. Dried dung
C. Sun
D. Natural gas
Answer» D. Natural gas
Explanation: Energy is broadly classified as commercial and non-commercial energy. Firewood, agricultural waste (straw, etc.) and animals waste (cowdung) are the important components of non-commercial energy. Coal, petroleum products, natural gas and, electricity are the important components of commercial energy. These goods are largely used for commercial purposes in the factories and farms.
556.

Which of the following is used to make light weight, but strong plastic?

A. Nylon
B. Polythene
C. Polyvinyl Chloride
D. Methyl Methacrylate
Answer» C. Polyvinyl Chloride
Explanation: Polyvinyl chloride (PVC) is a common, strong but lightweight plastic that is used in making tough plastic. It is used for flexible applications such as insulating cables. It is the third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene.
557.

Which gas emitted by power stations causes acid rain?

A. Carbon dioxide
B. Sulphur dioxide
C. Helium
D. Nitrogen
Answer» B. Sulphur dioxide
Explanation: Sulfur dioxide (SO2) and nitrogen oxides (NOx) are the principal pollutants that cause acid rain. SO2 and NOx emissions released to the air react with water vapor and other chemicals to form acids that fall back to Earth. Power plants burning coal and heavy oilproduce over two-thirds of the annual SO2 emission.
558.

Heavy water is –

A. Deuterium
B. Rain water
C. Tritium oxide
D. Deuterium oxide
Answer» D. Deuterium oxide
Explanation: Heavy water is deuterium oxide (2H2O). It is a form of water that contains a larger than normal amount of the hydrogen isotope deuterium (2H or D, also known as heavy hydrogen), rather than the common hydrogen-1 isotope (1H or H, also called protium) that makes up most of the hydrogen in normal water.
559.

Chemical composition of heavy water is –

A. H2O2
B. H2O
C. HDO
D. D2O
Answer» D. D2O
Explanation: The chemical composition of Heavy water (deuterium oxide) is 2H2O or D2O.
560.

The most abundant element is -

A. Calcium
B. Silicon
C. Oxygen
D. Nitrogen
Answer» C. Oxygen
Explanation: On earth, oxygen is the most common element, making up about 47% of the earth's mass. Silicon is second, making up 28%, followed by aluminum (8%), iron (5%), magnesium (2%), calcium (4%), sodium (3%), and potassium (3%). All of the remaining elements together make up less than 1% of the earth's mass.
561.

Aluminium salt commonly used to stop bleeding is -

A. Aluminium nitrate
B. Aluminium sulphate
C. Aluminium Chloride
D. Potash alum
Answer» B. Aluminium sulphate
Explanation: Alum (Aluminium Sulfate) is used to stop bleeding. For example, Styptic pencils containing aluminium sulfate are used as astringents to prevent bleeding from small shaving cuts. It constricts blood vessels to stop the flow of blood.
562.

Hydrochloric acid is also known as -

A. Galic acid
B. Picric acid
C. Muriatic acid
D. Chloric acid
Answer» C. Muriatic acid
Explanation: Hydrochloric acid was historically called acidum sails, muriatic acid, and spirits of salt because it was produced from rock salt and green vitriol and later from the chemically similar substances common salt and sulfuric acid. Hydrochloric acid is found naturally in gastric acid.
563.

The inert gas used as beacon light is -

A. Kr
B. Ar
C. He
D. Ne
Answer» D. Ne
Explanation: Neon is used in neon discharge lamps and advertising signs because the neon lights are visible from long distances. Since the light of neon signs has a better penetrating power through fog and mist, the neon signs are also used in beacon lights for the safety of air and sea navigation.
564.

Who proposed first atomic theory?

A. E.Rutherford
B. De Broglie
C. John Dalton
D. D.I.Mendeleef
Answer» C. John Dalton
Explanation: Democritus first suggested the existence of the atom but it took almost two millennia before the atom was placed on a solid foothold as a fundamental chemical object by John Dalton (1766-1844).
565.

The ultrapure metal is obtained by -

A. Calcination
B. Sublimation
C. zone refining
D. None of these
Answer» C. zone refining
Explanation: The principal stages in the production of ultrapure metals are the preparation of pure chemical compounds, the reduction of the compounds to the elementary state and further purification.
566.

Antacids are found in drugs that give relief to -

A. Eye sight
B. Stomach ache
C. Acne
D. Headache
Answer» B. Stomach ache
Explanation: An antacid is a substance which neutralizes stomach acidity. Antacids are taken by mouth to relieve heartburn, the major symptom of gastro-esophageal reflux disease, or acid indigestion which are a few of the common terms used to describe digestive upset.
567.

Heavy water is -

A. Monoterium oxide
B. Polyterium oxide
C. Deuterium oxide
D. Trisium oxide
Answer» C. Deuterium oxide
Explanation: Heavy water (D2O) is also called deuterium oxide. It is water composed of deuterium, the hydrogen isotope with a mass double that of ordinary hydrogen, and oxygen.
568.

Mark the compound which possesses ionic, covalent and coordinate bonds.

A. NH4C1
B. SO3
C. SO2
D. H2O
Answer» A. NH4C1
Explanation: Ammonium chloride (NH4Cl) is generally considered as an ionic compound but this compound has three different types of bond.
569.

Which of the following is the lightest metal?

A. Mercury
B. Silver
C. Lithiu
D. Lead
Answer» C. Lithiu
Explanation: The lightest or least dense metal that is a pure element is lithium, which has a density of 0.534 g/cm3. This makes lithium nearly half as dense as water, so if lithium was not so reactive, a chunk of the metal would float on water.
570.

Fuse wire is made of an alloy of             .

A. Lead and Copper
B. Tin and Copper
C. Tin and Lead
D. Copper and Silver
Answer» C. Tin and Lead
Explanation: The material used for making fuse element has a low melting point such as tin, lead, or zinc.
571.

The nuclear particle having no mass and no charge, but only spin is -

A. proton
B. neutrino
C. meson
D. electron
Answer» B. neutrino
Explanation: Neutrinos do not carry electric charge, and have mass quite small, though non- zero. Their mass is tiny even by the standards of subatomic particles. They are electrically neutral, weakly interacting elementary subatomic particles with half-integer spin.
572.

In a period from Li to F, ionisation potential –

A. cannot be predicted
B. increases
C. decreases
D. remains same
Answer» A. cannot be predicted
Explanation: 0
573.

A nibble is equal to –

A. 32
B. 4
C. 8
D. 16
Answer» B. 4
Explanation: In computing, a nibble is a four- bit aggregation, or half an octet. A nibble contains 4 bits.
574.

The non-metal found in the liquid state is –

A. bromine
B. nitrogen
C. fluorine
D. chlorine
Answer» A. bromine
Explanation: Bromine belongs to the halogen group. It is the only non-metal element that is in a liquid form at room temperature. At room temperature it is a reddish brown fuming liquid with an unpleasant chlorine like smell.
575.

Which of the following metals does NOT react with oxygen even at a high temperature?

A. Aluminium
B. Silver
C. Lead
D. line
Answer» B. Silver
Explanation: Silver and gold do not react with oxygen even at high temperatures as they are less reactive and are placed below the reactivity series.
576.

Acetic acid is know as -

A. Caustic soda
B. Spirit
C. Baking soda
D. Vinegar
Answer» D. Vinegar
Explanation: Acetic acid (CH3COOH) also called ethanoic acid, the most important of the carboxylic acids. Vinegar is roughly 3-9% acetic acid by volume making acetic acid the main component of vinegar apart from water.
577.

Which of the following gas is used in cigarette lighters?

A. Butane
B. Propane
C. Methane
D. Ethane
Answer» A. Butane
Explanation: Butane, a highly flammable, colorless, easily liquefied gas used in gas-type lighters and butane torches. Naphtha, a volatile flammable liquid hydrocarbon mixture used in wick-type lighters and burners.
578.

Which one among the following is-used as a moderator in nuclear reactors?

A. Ozone
B. Heavy hydrogen
C. Heavy water
D. Hydrogen peroxide
Answer» C. Heavy water
Explanation: Heavy water is used in certain types of nuclear reactors, where it acts as a neutron moderator to slow down neutrons so that they are more likely to react with the fissile uranium-235 than with uranium238.
579.

The chemical name of baking soda is -

A. Sodium carbonate
B. Sodium bicarbonate
C. Sodium chloride
D. Sodium nitrate
Answer» B. Sodium bicarbonate
Explanation: Sodium bicarbonate (NaHCO3) is also known as baking soda. It is a chemical leavening agent which is added to baked goods before cooking to produce carbon dioxide and cause them to 'rise'.
580.

Chemical name of common salt is –

A. Sodium Chloride
B. Sodium Bicarbonate
C. Sodium
D. Sodium Oxide
Answer» A. Sodium Chloride
Explanation: Sodium chloride, also known as salt, common salt, table salt or halite, is an ionic compound with the chemical formula NaCl, representing equal proportions of sodium and chlorine. In the form of table salt, it is commonly used as a condiment and food preservative.
581.

Nitrogen in water is commonly found in the form of -

A. Nitrous oxide
B. Nitrate
C. Nitric oxide
D. Nitrite
Answer» B. Nitrate
Explanation: Nitrate (NO3) is the most common form of inorganic nitrogen in unpolluted waters. Nitrate moves readily through soils and into ground water, where concentrations can be much higher than insurface waters. Water in coastal areas mainly contains elementary nitrogen gas (N2).
582.

Chemical name of Gammaxane is -

A. Toluene
B. Chloro benzene
C. Aniline
D. Benzene hexachloride
Answer» D. Benzene hexachloride
Explanation: Gammexane is an insecticide that is the gamma isomer of benzene hexachloride. It is also known as lindane. Benzene hexachloride is any of several stereoisomers of 1,2,3,4,5,6- hexachlorocyclohexane formed by the light- induced addition of chlorine to benzene.
583.

The acid which fails to liberate carbon dioxide from sodium bicarbonate is :

A. Acetic acid
B. Formic acid
C. Carbonic acid
D. Sulphuric acid
Answer» D. Sulphuric acid
Explanation: Sodium bicarbonate and organic acid (Formic acid, Acetic acid, Carbonic acid, etc) react vigorously to liberate carbon dioxide. For example, Sodium bicarbonate (NaHCO3) when treated with acetic acid reacts vigorously to liberate carbon dioxide.
584.

Which one of the following is not coal variety?

A. Lignite
B. Bituminous
C. Dolomite
D. Peat
Answer» C. Dolomite
Explanation: Dolomite is a common rock- forming mineral. It is a calcium magnesium carbonate with a chemical composition of CaMg(CO3)2. It is the primary component of the sedimentary rock known as dolostone and the metamorphic rock known as dolomitic marble. Dolomite is used in the Pidgeon process for the production of magnesium.
585.

Which of the following is the strongest base in aqueous solution?

A. Diethylamine
B. Triethylamine
C. Ammonia
D. Ethylamine
Answer» A. Diethylamine
Explanation: Amines are organic derivatives of ammonia, in which one, two, or all three of the hydrogens of ammonia are replaced by organic groups. All aliphatic primary amines are stronger bases than ammonia.
586.

The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is -

A. Xenon
B. Krypton
C. Argon
D. Helium
Answer» D. Helium
Explanation: Trimix is a breathing gas, consisting of oxygen, helium and nitrogen, and is often used in deep commercial diving. The helium is included as a substitute for some of the nitrogen, to reduce the narcotic effect of the breathing gas at depth. It helps to reduce nitrogen narcosis and to avoid the dangers of oxygen toxicity. With a mixture of three gases, it is possible to create mixes suitable for different depths or purposes by adjusting the proportions of each gas.
587.

Which of the following substance’s smell is similar to Ethanoic acid?

A. Tomatojuice
B. Kerosene
C. Vinegar
D. Lemon
Answer» C. Vinegar
Explanation: Acetic acid, also known as ethanoic acid, is an organic chemical compound best recognized for giving vinegar its sour taste and pungent smell. Vinegar is roughly 3-9%acetic acid by volume, making acetic acid the main component of-vinegar apart from water.
588.

A powerful eye irritant present in smog is –

A. nitric oxide
B. sulphur dioxide
C. peroxyacetyl nitrate
D. carbon dioxide
Answer» C. peroxyacetyl nitrate
Explanation: Peroxyacetyl nitrate is a secondary pollutant present in photochemical smog. It is thermally unstable and decomposes into peroxyethanoyl radicals and nitrogen dioxide gas. It is a lachrymatory substance.
589.

The most important ore of lead is –

A. Galena
B. Magnetite
C. Pyrolusite
D. Siderite
Answer» A. Galena
Explanation: Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral. Galena is one of the most abundant and widely distributed sulfide minerals.
590.

The gas used to dilute oxygen for breathing by deep sea divers is-

A. Neon
B. Argon
C. Nitrogen
D. Helium
Answer» D. Helium
Explanation: Helium is used since it has very low (almost non-existent) narcotic properties. The nitrogen in air is highly narcotic at depth and adding helium allows one to dive without the effects of narcosis (where one's mind is impaired).
591.

Maximum permissible concentration of copper in drinking water in mg/L is -

A. 0.01
B. 0.05
C. 1.0
D. 2.0
Answer» C. 1.0
Explanation: In the first edition of the Guidelines for Drinking Water Quality, published in 1984, a guideline value of 1.0 mg/litre was established for copper, based on its laundry and other staining properties.
592.

Which of the following is biode- gradable?

A. Paper
B. D.D.T.
C. Aluminium
D. Plastic
Answer» A. Paper
Explanation: Paper is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets.
593.

The ‘Green House effect' is produced due to the presence of excess amount of –

A. Sulphur dioxide
B. Nitrogen dioxide
C. Carbon monoxide
D. Methane
Answer» D. Methane
Explanation: By their percentage contribution to the greenhouse effect on Earth the four major gases are: Water vapour (36-70%), Carbon dioxide (9-26%), Methane (4-9%) and Ozone (3- 7%).
594.

Which of the following acids serves as an electrolyte in a lead storage battery?

A. Sulphuric acid
B. Lactic acid
C. Hydrochloric acid
D. Nitric acid
Answer» A. Sulphuric acid
Explanation: Dilute sulfuric acid (H2SO4) serves as the electrolyte in a lead-acid battery. Dilute sulfuric acid used for lead acid battery has ratio (to water) of 3:1 other components of the battery include: Lead peroxide (PbO2) and Sponge lead (Pb).
595.

Which of the following is a natural polymer?

A. Bakelite
B. Nylon
C. Polythene
D. Starch
Answer» D. Starch
Explanation: Cotton, starch, cellulose and rubber are some of the naturally occurring polymers. Starch is a condensation polymer made up of hundreds of glucose monomers, which split out water molecules as they chemically combine. Starch is a member of the basic food group carbohydrates and is fourid in cereal grains and potatoes. It is also referred to as a polysaccharide, because it is a polymer of the monosaccharide glucose.
596.

Which one of the following nonmetals shows allotropy in the liguid state?

A. Carbon
B. Sulphur
C. Phosphorous
D. Bromine
Answer» B. Sulphur
Explanation: Sulphur is a non-metal that shows allotropy in the liquid state. If sulphur is heated slowly the changes between the different forms can be observed. These changes are in the form of colour and viscosity (thickness) of the liquid. If the dark brown liquid sulphur is poured into a beaker of cold water, plastic sulphur is formed. This is an elastic, rubber-like form of sulphur.
597.

Atoms of same element having different mass numbers are Called               .

A. Isobars
B. Isotopes
C. (3)Isotones
D. (4) Isomers
Answer» B. Isotopes
Explanation: Atoms that have the same atomic number but different atomic masses are called isotopes. The difference in mass arises due to the atoms containing a different number of neutrons for the same number of protons. For example, carbon-12, carbon-13 and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13 and 14 respectively.
598.

Bee sting contains -

A. An acidic liquid
B. asalt solution
C. an alkaline liquid
D. acorrosive liquid
Answer» A. An acidic liquid
Explanation: A bee sting is a sting from a bee (honey bee, bumblebee, sweat bee, etc.). Bee stings are acidic. So its effects can be neutralized with bicarbonate of soda or alkali and this reaction reduces the pain.
599.

The nuclear reaction in which a heavy nucleus splits into two nuclei of nearly equal mass is called -

A. Nuclear fusion
B. Nuclear fission
C. Nuclear reaction
D. Fast breeding
Answer» B. Nuclear fission
Explanation: Nuclear fission is a process used to create energy. It is when an atom splits apart into smaller atoms. The process gives off a lot of energy, and is used in nuclear weapons and nuclear reactors.
600.

Which element found in all organic compounds?

A. carbon
B. nitrogen
C. calcium
D. none of them
Answer» A. carbon
Explanation: Carbon is found in all organic matter, but NOT in inorganic matter organic means chemical compounds with carbon in them. In a more general sense, organic refers to living things.
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