1240+ Chemistry Solved MCQs


Non-metallic character increases from

A. Magnesium to Barium
B. Potassium to Cesium
C. Oxygen to Selenium
D. Sodium to Chlorine
Answer» D. Sodium to Chlorine
Explanation: The elements which lose electrons to form cations are known as metals. Metallic character decreases across a period as we move from left to right.

In organic compounds, nitrogen is estimates by -

A. Dumas method
B. Carius method
C. Victor-meyer's method
D. Liebig's method
Answer» A. Dumas method
Explanation: 0

Which one is the pure element?

A. glass
B. cement
C. sodium
D. none of these
Answer» C. sodium
Explanation: A pure element is a chemical element consisting of only one stable isotope.

The most electropositive elements among the following is :

A. Cs
B. Ca
C. Na
D. Br
Answer» A. Cs
Explanation: The alkali metals are the most electropositive. Cesium is the most electropositive of the stable elements.Francium, while unstable, is theoretically the most electropositive element.

Which is Known as carbolic acid?

A. Phenol
B. Ethanol
C. Acetic acid
D. Oxalic acid
Answer» A. Phenol
Explanation: Phenol is also known as carbolic acid. It is an aromatic organic compound with the molecular formula C6H5OH. Phenol and its chemical derivatives are essential for production of polyearbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs.

Atomic explosion is triggered by -

A. thermo nuclear reaction
B. chemical reaction
C. controlled chain reaction
D. uncontrolled chain reaction
Answer» D. uncontrolled chain reaction
Explanation: During an uncontrolled nuclear chain reaction such as atomic explosion, a radioactive substance gives off energy at a rate that increases rapidly with time, leading to large amounts of radiation and possibly an explosion. The radioactive decay of one atom triggers the decay of some of its neighbors, in turn setting off other atoms; thus, producing large amounts of energy.

Stalactites and Stalagmites form due to the precipitation of :

A. CaCO3
B. CaCl2
C. MgCl2
D. MgCO3
Answer» A. CaCO3
Explanation: Stalactites and stalagmites are formed by water dripping or flowing from fractures on the ceiling of a cave. The dominant mineral in them is calcite (calcium carbonate) or CaCaO3. Their largest displays are formed in caves of limestone and dolomite. Other minerals that may be deposited include other carbonates, opal, chalcedony, limonite, and some sulfides.

Fullerenes form a class of carbon allotropes. The first one to be identified was -

A. C-59
B. C-60
C. C-61
D. C-69
Answer» B. C-60
Explanation: The first fullerene to be identified was C-60 which has carbon atoms arranged in the shape of a football. Since this looked like the geodesic dome designed by the US architect Buckminster Fuller, the molecule was named fullerene.

Which one of the following is found in Vinegar?

A. Acetic acid
B. Propionic acid
C. Formic acid
D. Butyric acid
Answer» A. Acetic acid
Explanation: Vinegar is a liquid consisting mainly of acetic acid (CH3COOH) and water. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. It is mainly used as a cooking ingredient.

The gas produced in marshy places due to decomposition of vegetation is –

A. Carbon monoxide
B. Carbon dioxide
C. Sulphur dioxide
D. Methane
Answer» D. Methane
Explanation: Methane gas is a hydrocarbon gas largely composed of methane formed when organic material or vegetation decays in the absence of air. Naturally occurring methane is mainly produced by the process of methanogenesis. It is also known as Swamp Gas.

The chemical name of "Hypo" commonly used in photography is –

A. Sodium thiosulphate
B. Silver nitrate
C. Sodium nitrate
D. Silver iodide
Answer» A. Sodium thiosulphate
Explanation: An emulsion of sodium thiosulfate is called hypo by photographers. It is used to stop development of exposed film. Thiosulfate converts undeveloped silver bromide grains in the film into water-soluble silver thiosulfate complexes that can be removed when the film is washed.

The process of improving the quality of rubber by heating it with sulphur is called.

A. Vulcanization
B. Acceleration
C. Sulphonation
D. Galvanization
Answer» A. Vulcanization
Explanation: Vulcanization is a chemical process for converting natural rubber into more durable materials via the addition of sulfur or other equivalent curatives or accelerators. These additives modify the polymer by forming cross- links (bridges) between individual polymer chains.

Which of the following is not a noble gas?

A. Hydrogen
B. Helium
C. Neon
D. Argon
Answer» A. Hydrogen
Explanation: The noble gases are the chemical elements in group 18 of the periodic table. This chemical series contains helium, neon, argon, krypton, xenon, and radon.

Piped Natural Gas (PNG) is used for –

A. Mining
B. Welding
C. Anaesthesia
D. Cooking
Answer» D. Cooking
Explanation: PNG is mainly methane - CH4 with a small percentage of other higher hydrocarbons. The ratio of carbon to hydrogen is least in methane and hence it burns almost completely making it the cleanest fuel. Domestic PNG customers, also known as Residential customers, use has for cooking purpose and also for heating water through gas geysers.

Which of the following elements is not present in stainless steel?

A. Iron
B. Tungsten
C. Chromium
D. Nickel
Answer» B. Tungsten
Explanation: Stainless steel is defined as a steel alloy of iron with a minimum of 10.5% to 11% chromium content by mass. There are different types of stainless steels: when nickel is added, for instance, the austenite structure of iron is stabilized. This crystal structure makes such steels virtually non-magnetic and less brittle at low temperatures.

Which of the inert gases can form compounds?

A. Helium
B. Xenon
C. Krypton
D. Argon
Answer» B. Xenon
Explanation: Xenon compounds are the most numerous of the noble gas compounds that have been formed. Most of them have the xenon atomin the oxidation state of +2, +4, +6, or +8 bonded to highly electronegative atoms such as fluorine or oxygen. Some of these compounds have found use in chemical synthesis as oxidizing agents.

Burning pyrites ore gives out –

A. Carbon dioxide gas
B. Sulphur dioxide gas
C. Nitrogen dioxide gas
D. Nitric oxide gas
Answer» B. Sulphur dioxide gas
Explanation: The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS9. Pyrite remains in commercial use for the production of sulfur dioxide, for use in such applications as the paper industry, and in the manufacture of sulfuric acid.

Milk is -

A. Emulsion
B. Suspension
C. Foam
D. Gel
Answer» A. Emulsion
Explanation: An emulsion is a mixture of two liquids that cannot combine into a solution. In the case of milk, butterfat globules are suspended in a water-based fluid. The globules are encased in membranes that prevent them from combining into giant lumps of butterfat.

Anaemia is caused because of deficiency of which of the following?

A. Cobalt
B. Iron
C. Sodium
D. Calcium
Answer» B. Iron
Explanation: Anemia is a condition that develops when blood lacks enough healthy red blood cells or hemoglobin. The three main types of anemia are due to blood loss, decreased red blood cell production, and increased red blood cell break down.

Compound having tetrahedral structure is             .

A. C2H4
B. C2H2
C. CH4
D. None of these
Answer» C. CH4
Explanation: Methane is a tetrahedral molecule with four equivalent C-H bonds. Its electronic structure is described by four bonding molecular orbital resulting from the overlap of the valence orbitals on C and H.

Which of the following is produced during the formation of photochemical smog?

A. Nitrogen Oxides
B. Hydrocarbons
C. Methane
D. Ozone
Answer» D. Ozone
Explanation: Ozone is produced during the formation of photochemical smog. Photochemical smog is a mixture of pollutants that are formed when nitrogen oxides and volatile organic compounds (VOCs) react to sunlight, creating a brown haze above cities.

Benzene cannot undergo –

A. Substitution
B. Addition
C. Elimination
D. Oxidation
Answer» C. Elimination
Explanation: Benzene can not undergo Elimination reaction.

The polymer obtained by the condensation of hexamethylene diamine and adipic acid is –

A. Nylon 66
B. Terylene
C. Tollen's
D. Bakelite
Answer» A. Nylon 66
Explanation: Polymers are very high molecular mass substances each molecule of which consists of very large number of simple structural units joined together though covalent bonds in a regular fashion. Polymers whose repeating structural unit are derived from two or more types of monomer units are called copolymers. For examples, in case of nylon 66, the repeating structural unit is derived from two monomer units - hexamethylenediamine and adipic acid.

The antiseptic compound present in dettol is –

A. Iodine
B. Enloroxylenol
C. Biothional
D. Cresol
Answer» B. Enloroxylenol
Explanation: The active ingredient in Dettol that confers its antiseptic property is chloroxylenol (C8H9ClO), an aromatic chemical compound. Chloroxylenol comprises 4.8% of Dettol's total mixture, with the rest composed of pine oil, isopropanol, castor oil soap, caramel and water.

Amniocentesis is a technique used -

A. to determine the sex of fetus
B. to test of amino acid
C. to test brain
D. None of the above
Answer» A. to determine the sex of fetus
Explanation: Amniocentesis (also referred to as amniotic fluid test) is a medical procedure used in prenatal diagnosis of chromosomal abnormalities and fetal infections, and also for sex determination.

Bonds formed by the sharing of an electron pair between two atoms are known as -

A. Covalent bonds
B. Ionic bonds
C. Weak bonds
D. None of the above
Answer» A. Covalent bonds
Explanation: Bonds which are formed by the sharing of an electron pair between two atoms are known as covalent bonds.

The pH of lemon juice is expected to be

A. equal to 7
B. nothing can be predicted
C. less than 7
D. more than 7
Answer» C. less than 7
Explanation: The pH level of lemon juice is, 2.00 to 2.60. It varies depending on the lemon. pH expresses different levels of acidity or alkalinity within a solution.

An example of heterocyclic compound is –

A. Naphthalene
B. Furan
C. Benzene
D. Anthracene
Answer» B. Furan
Explanation: A heterocyclic compound is a cyclic compound that has atoms of at least two different elements as members ails ring (s). Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen.

The pair of compounds used as anesthetic in medicines –

A. Ether, Ammonia
B. Nitrous oxide, Chloroform
C. Chloroform, Nitrogen dioxide
D. Nitrogen dioxide, ether
Answer» B. Nitrous oxide, Chloroform
Explanation: Nitrous oxide is one of the more well-known anesthetic gases, and has been in use for around 200 years. Unlike some other anesthetics, this compound can be used both for inducing unconsciousness and pain control. Chloroform is more potent and more toxic than ether. Its use as an anaesthetic decreased with increased experience and knowledge of its dangers.

pH scale ranges from –

A. 0 - 7
B. 8 - 14
C. 0 - 14
D. None
Answer» C. 0 - 14
Explanation: The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic. The pH scale is logarithmic and as a result, each whole pH value below 7 is ten times more acidic than the new higher value.

Glass is -

A. Super cooled liquid
B. Crystalline solid
C. Liquid crystal
D. None of these
Answer» A. Super cooled liquid
Explanation: Glass is sometimes called a Super cooled liquid because it does not form a crystalline structure, but instead forms an amorphous solid that allows molecules in the material to continue to move.

The sum of potential energy and kinetic energy is known as :

A. Electrical energy
B. Chemical energy
C. Light energy
D. Mechanical energy
Answer» D. Mechanical energy
Explanation: In physical sciences, mechanical energy is the sum ofpotential energy and kinetic energy. It is the energy associated with the motion and position of an object.

Carborundum is another name of –

A. Silicon carbide
B. Silicon oxide
C. Calcium carbide
D. Calcium oxide
Answer» A. Silicon carbide
Explanation: Silicon carbide, also known as carborundum, is a compound of silicon and carbon with chemical formula SiC. It occurs in nature as the extremely rare mineral moissanite. Silicon carbide powder has been massproduced since 1893 for use as an abrasive.

Number of neutrons in an atom of hydrogen is -

A. One
B. Zero
C. Two
D. Three
Answer» B. Zero
Explanation: Neutrons are the particles in an atom that have a neutral charge. So, if an atom has equal numbers of electrons and protons, the charges cancel each other out and the atom has a neutral charge. Hydrogen (H) has 1 proton and 1 electron; it does not have any neutron in its nucleus.

Peroxyacetyl nitrate is a –

A. Acidic dye
B. Plant hormone
C. Vitamin
D. Secondary pollutant
Answer» D. Secondary pollutant
Explanation: Peroxyacetyl nitrate is a secondary pollutant present in photochemical smog (a mixture of air pollutants) that includes both gases and particulates. It is thermally unstable and decomposes into peroxy-ethanoyi radicals and nitrogen dioxide gas. It is a lathIymatory substance.

The term 'brown air' is used for –

A. Acid fumes
B. Photochemical smog
C. Sulphurous smog
D. Industrial smog
Answer» B. Photochemical smog
Explanation: Photochemical smog which is mainly composed of ozone (O3), Peroxyacetyl nitrate (PAN) and No., is also known as brown air where solar radiation is intense. In seasons of lesser solar radiation or areas, smog formation is incomplete and the air is referred to as grey air.

Soldering of two metals is possible because of the property of –

A. Viscosity
B. Osmosis
C. Cohesion
D. Surface tension
Answer» C. Cohesion
Explanation: Soldering is the process of joining two metals by the use of a solder alloy, and it is one of the oldest known joining techniques. It is possible because of the property of cohesion, the interaction between adjacent parts of the same body and as acting through-out the interior of substance. Soldering leads to alloy formation at the layer between two metals.

n electrochemical cell which is used as a source of direct electrical current at constant voltage under standard conditions is called a –

A. Power transmittor
B. Battery
C. Uninterrupted power supply (UPS)
D. Generator
Answer» C. Uninterrupted power supply (UPS)
Explanation: A Galvanic cell, also known as battery, is an electro-chemical cell that derives electrical energy from spontaneous redox reactions taking place within the cell. It is typically used as a source of electrical power. By their nature, they produce direct current. A battery is a set of galvanic cells that are connected in parallel.

Which method will be employed to test the hardness of water?

A. Boiling
B. Distillation
C. Formation of lather with soap
D. None of these
Answer» C. Formation of lather with soap
Explanation: 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.

J.J. Thomson’s proposed model of action is generally called              model.

A. Cream and cake
B. Plum and pudding
C. Plum and cake
D. Cream and pudding
Answer» B. Plum and pudding
Explanation: The plum pudding model, one of several scientific models of the atom, was first proposed by J. J. Thomson in 1904 soon after thediscovery of the electron, but before the discovery of the atomic nucleus. In this model, atoms were known to consist of negatively charged electrons. The model represented an attempt to consolidate the known properties of atoms at the time.

Even after sunset, the air near the Earth's surface continue to receive heat due to –

A. Insolation
B. Terrestrial Radiation
C. Conduction
D. Convection
Answer» B. Terrestrial Radiation
Explanation: Even after the sunset when the sun goes down, the incoming radiation from the sun stops, but there is still a lot of radiation that has been absorbed by the earth, which is reradiated in form of terrestrial radiation Energy leaving the earth's surface i.e. terrestrial radiation heats up the atmosphere more than the incoming solar radiation i.e. insolation

Trinitrotoluene is –

A. used to melt metals
B. used to fuse two metals
C. used as an abrasive
D. used as an explosive
Answer» D. used as an explosive
Explanation: Trinitrotoluene (C6H2 (NO2)3.CH3), abbreviated as TNT, is sometimes used as a reagent in chemical synthesis, but it is best known as an explosive material with convenient handling properties. The explosive yield of TNT is considered to be the standard mea-sure of bombs and other explosives.

Which one of the following polymers is widely used for making bullet proof material?

A. Polyvinyl chloride
B. Polyamides
C. Polyethylene
D. Polycarbonates
Answer» D. Polycarbonates
Explanation: Ballistic nylon was the standard cloth used for bulletproof vests until the 1970s. In 1965, Stephanie Kwolek, a chemist at Du Pont, invented Kevlar, trademark for poly-para- phenylene terephthalamide, a liquid polymer that can be spun into aramid fiber and woven into cloth.

The high reactivity of fluorine is due to

A. small size of fluorine atom
B. its high electro negativity
C. availability of d-orbitals
D. strong F - F bond
Answer» B. its high electro negativity
Explanation: The high reactivity of fluorine is due to its high electro negativity.

Which of the following is not an example of a biomass energy source?

A. Wood
B. Ethanol
C. Cow dung
D. Atomic energy
Answer» D. Atomic energy
Explanation: The organic matter within the plants, the agriculture crops, and material related with the plants directly or in directly are called as the biomass.

Which of the following has the highest bond order?

A. N2
B. O2
C. Cl2
D. H2
Answer» A. N2
Explanation: A high bond order indicates more attraction between electrons. A higher bond order also means that the atoms are held together more tightly.

             is used for making vinegar.

A. Tartaric acid
B. Mahe acid
C. Oxalic acid
D. Acetic acid
Answer» D. Acetic acid
Explanation: Vinegar is a liquid consisting mainly of acetic acid (CH3COON) and water. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. It is mainly used as a cooking ingredient.

Major portion of the earth's crust is mainly constituted by –

A. Oxygen and Iron
B. Oxygen and Silicon
C. Silicon and Iron
D. Silicon and Aluminium
Answer» B. Oxygen and Silicon
Explanation: Oxygen is the most abundant element in the earth's crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust. Given the abundance of oxygen and silicon, the silicates are the most abundant minerals in the earth's crust.

Cinnabar is an ore/mineral of –

A. Lead
B. Manganese
C. Molybdenum
D. Mercury
Answer» D. Mercury
Explanation: Cinnabarrefers to the common bright scarlet to brick red form of mercuryasullide (HgS) that is the most common source ore for refining elemental mercury. It is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments.

Which among the following is not a characteristic of transition metals?

A. Tendency to gain electrons
B. Low electronegativity
C. Low ionization energy
D. Malleability
Answer» A. Tendency to gain electrons
Explanation: The transition metals have a tendency to lose electrons. Since the electrons in the highest energy level are actually on a lower principal enemy number than the ones before them, this makes it relatively easy to lose some or all of their electrons to land in stable slate. When these metals form ions, the 4s electrons are always lost first; so, they form only cations (positive ions).

Human nails are made up of -

A. Pigment
B. Elastin
C. Albumin
D. Keratin
Answer» D. Keratin
Explanation: Keratin, a family of fibrous structural proteins, is the key structural component of hair and nails.

Meson particles are found in-

A. R-rays
B. X-rays
C. Laser beam
D. Cosmic rays
Answer» D. Cosmic rays
Explanation: Meson, any member of a family of subatomic particles composed of a quark and an antiquark. Mesons are sensitive to the strong force, the fundamental interaction that binds the components of the nucleus by governing the behavior of their constituent quarks.

Nitric acid does not react with -

A. Gold
B. Copper
C. Zinc
D. Iron
Answer» A. Gold
Explanation: Concentrated nitric acid is a very strong oxidator capable of reacting with the noble metals such as copper or silver. Some precious metals, such as pure gold and platinum- group metals do not react with nitric acid. However, pure gold does react with aqua regia, a mixture of concentrated nitric acid and hydrochloric acid.

The process of dissolving an acid or a base in water is a highly -

A. Exothermic reaction
B. Endothermic reaction
C. Sublimation reaction
D. Redux reaction
Answer» A. Exothermic reaction
Explanation: The process of dissolving an acid or a base in water is a highly exothermic one. This is why care must be taken while mixing concentrated nitric acid or sulphuric acid with water.

Atomic number is equal to -

A. Number of electrons
B. Number of neutron
C. Number of protons
D. Total number of protons and neutrons
Answer» C. Number of protons
Explanation: Atomic number is equal to Number of protons. The atomic number or proton number of a chemical element is the number of protons found in the nucleus of an atom.

Which of the following does the Nucleus of an atom consist of?

A. Protons and neutrons
B. Protons and electrons
C. Electrons
D. Protons
Answer» A. Protons and neutrons
Explanation: The nucleus is the small, dense region consisting of protons and neutrons at the center of an atom. Protons and neutrons are bound together to form a nucleus by the nuclear force. The atomic nucleus was discovered in 1911 by Ernest Rutherford based on the 1909 Geiger-Marsden gold foil experiment.

The gas dissolved in water that makes it basic is –

A. ammo
B. sulphur dioxide
C. hydrogen
D. carbon dioxide
Answer» B. sulphur dioxide
Explanation: Ammonia has that dissolves in water forms a solution of ammonium hydroxide (NH4OH). This solution (including the gas) is a strong base and will make the solution alkaline.

The number of hydrogen bonds between guanine and cytosine in DNA is –

A. 2
B. 3
C. 4
D. 1
Answer» B. 3
Explanation: The chemistry of the nitrogenous bases is really the key to the function of DNA. It allows something called complementary base pairing. Cytosine can form three hydrogen bonds with guanine, and adenine can form two hydrogen bonds with thymine.

What happens when a drop of glycerol is added to crushed KMnO4 spread on a paper?

A. There is a crackling sound
B. There is a violent explosion
C. There is no reaction
D. The paper ignites
Answer» B. There is a violent explosion
Explanation: When solid Potassium Permanganate (KMnO4) is mixed with pure glycerol or other simple alcohols, it will result ina violent combustion reaction. Potassium Permanganate is an extremely powerful oxidizer which spontaneously ignites after coming in contact with glycerol.

Most commonly used bleaching agent is –

A. Sodium chloride
B. Alcohol
C. Carbon dioxide
D. Chlorine
Answer» D. Chlorine
Explanation: Chlorine is used to disinfect water and is part of the sanitation process for sewage and industrial waste. During the production of paper and cloth, it is used as a bleaching agent. It is also used in cleaning products; including household bleach which is chlorine dissolved in water Bleaching powder is an important and a commonly used bleaching agent prepared from chlorine.

The heat value of combustion of Gasoline is -

A. 12600 kJ/kg
B. 14600 kJ/kg
C. 39400 kJ/kg
D. 47000 kJ/kg
Answer» D. 47000 kJ/kg
Explanation: The calorific value of Gasoline is 47,300 kJ/kg. The calorific value of a fuel is the quantity of heat produced by its combustion - at constant pressure and under "normal" conditions (i.e. to 0°C and under a pressure of 1,013 mbar).

Who developed the model of atomic structure?

A. Bohr and Rutherford
B. Volta
C. Alfred Nobel
D. Faraday
Answer» A. Bohr and Rutherford
Explanation: In 1911 Ernest Rutherford used experimental evidence to show that an atom must contain a central nucleus. Niels Bohr further developed Rutherford's nuclear atommodel. He used experimental evidence to support the idea that electrons occupy particular orbits or shells around the nucleus of an atom.

Which of the following is the main compound of voter ink?

A. Silver nitrate
B. Ammonium Chloride
C. Silver Chloride
D. Ammonium Nitrate
Answer» A. Silver nitrate
Explanation: The chemical used in voting inks is silver nitrate. Silver nitrate is preferred because it is soluble in water, and makes an inky black solution. When put on the skin, silver nitrate reacts with the salt present on it to form silver chloride that is insoluble in water, and clings to the skin, making it impossible to wash off with soap and water or even alcohol. Mysore Paints and Varnish Limited in Karnataka is only company in India authorised to produce the indelible ink.

What is a common name for the substance which irritates lachrymal glands?

A. Tear Gas
B. Laughing Gas
C. Anaesthetic Gas
D. Noble Gas
Answer» A. Tear Gas
Explanation: Lacrimal gland, located under the upper eyelid at the outer cornea of the eye, is responsible for tearing during emotional stimulation or following corneal irritation by a foreign body or chemical substance. Tear gas, also called lacrimator, refers to any of a group of substances that irritate the mucous membranes of the eyes, causing a stinging sensation and tears. It produces severe lacrimation by irritating the conjunctivae.

Diamond is the form of carbon that is -

A. Crystalline
B. Amorphous
C. Chemical
D. Alkaline
Answer» A. Crystalline
Explanation: Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic.

Which of the following does not give benzoic acid on hydrolysis?

A. phenyl cyanide
B. benzoyl chloride
C. benzyl chloride
D. methyl benzoate
Answer» C. benzyl chloride
Explanation: Hydrolysis is any chemical reaction in which a molecule of water ruptures one or more chemical bonds.

Which of the following gases is known as “Laughing Gas”?

A. Nitrous oxide
B. Nitrogen peroxide
C. Nitrogen
D. Nitric oxide
Answer» A. Nitrous oxide
Explanation: Nitrous oxide (N2O) is commonly known as laughing gas. It is used in surgery and dentistry for its anaesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anaesthetic.

Inert gases are -

A. Miscible with water
B. Not stable
C. Chemically uncreative
D. Chemically very active
Answer» C. Chemically uncreative
Explanation: An inert gas is a gas which does not undergo chemical reactions since their valence shells are filled, meaning they don't normally form chemical bonds with other elements. They are extremely stable; they rarely gain, lose or share electrons. The inert gases, also called noble gases, are argon, helium, neon, krypton, xenon and radon.

The metallic constituents of hard water are -

A. Magnesium, Calcium and tin
B. Iron, tin and calcium
C. Calcium, magnesium and iron
D. Magnesium, tin and iron
Answer» C. Calcium, magnesium and iron
Explanation: Hard water is water that has high mineral content (in contrast with "soft water"). Hard water is formed whenwater percolates through deposits of limestone and chalk which are largely made up of calcium and magnesium carbonates.

Ruby and sapphire are oxides of -

A. capper
B. tin
C. iron
D. aluminium
Answer» D. aluminium
Explanation: Ruby and sapphire are oxides of aluminium. They are the important gems used in finger rings.

Water has maximum density at –

A. -4°C
B. 0°C
C. 4°C
D. 100°C
Answer» C. 4°C
Explanation: When cooled from room temperature liquid water becomes increasingly dense, as with other substances, but at approximately 4 °C (39 °F), pure water reaches its maximum density.

           gives hardness to stainless steel.

A. Zinc
B. Lead
C. Carbon
D. Tin
Answer» C. Carbon
Explanation: Iron is alloyed with carbon to make steel and has the effect of increasing the hardness and strength of iron.

The ‘solid waste’ is also known as -

A. Sedge
B. Toxic waste
C. Sludge
D. Scrubber
Answer» C. Sludge
Explanation: Solid waste, also known as sludge, refers to the residual, semi-solid material that is produced as a byproduct during sewage treatment of industrial or municipal wastewater. It mainly results from manufacturing process such as that of factories, industries, mills, and mining operations.

Which of the following has pH value 7?

A. Pure Water
B. H2SO4
C. Sodium Carbonate
D. HCl
Answer» A. Pure Water
Explanation: In chemistry, pH is a numeric scale used to specify the acidity or basicity of an aqueous solution. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. Pure water is neutral, being neither an acid nor basic; so it has pH value of 7.

Chemical name of vinegar is -

A. Acetone
B. Acetic acid
C. Formaldehyde
D. Ethanol
Answer» B. Acetic acid
Explanation: Vinegar is roughly 3-9% acetic acid CH3COOH) by volume, making acetic acid the main component of vinegar apart from water. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. Vinegar is mainly used as a cooking ingredient, or in pickling.

Mercury is a –

A. solid metal
B. liquid metal
C. solid non-metal
D. liquid non-metal
Answer» B. liquid metal
Explanation: A heavy, silvery d-block element, Mercury is the only metal that is liquid at standard conditions for temperature and pressure; the only other element that is liquid under these conditions is bromine. With a freezing point of -38.83 °C and boiling point of 356.73 °C, mercury has one of the narrowest ranges of its liquid state of any metal.

Spirit in contact with body gives cool sensation because it is –

A. liquid
B. transparent
C. highly volatile
D. a good conductor
Answer» C. highly volatile
Explanation: Spirit is very volatile. So when it is exposed, it evaporates rapidly to the air if released into the environment, producing a cool effect.

Natural rubber is the polymer of :

A. Isoprene
B. Styrene
C. Butadiene
D. Ethylene
Answer» A. Isoprene
Explanation: Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4- polyisoprene—a synthetic version of natural rubber.

In addition to hydrogen, the other abundant element present on Sun’s surface is -

A. Helium
B. Neon
C. Argon
D. Oxygen
Answer» A. Helium
Explanation: The Sun is composed primarily of the chemical elements hydrogen and helium; they account for 74.9% and 23.8% of the mass of the Sun in the photosphere, respectively. All heavier elements, called metals in astronomy, account for less than 2% of the mass. The Sun inherited its chemical composition from the interstellar medium out of which it formed: the hydrogen and helium in the Sun were produced by Big Bang nucleosynthesis.

If lime water is kept in the air, it turns milky due to presence of –

A. Carbondioxide
B. Nitrogen
C. Oxygen
D. Sulphurdioxide
Answer» A. Carbondioxide
Explanation: Lime water is calcium hydroxide (Ca(OH)2). When carbon dioxide is passed into it, it turns milky because of the formation of calcium carbonate: Ca(OH)2 + CO2 = CaCO3 +H2O

Heavy metal pollution of water is caused by:

A. Paints
B. Wood burning
C. Acid Plants
D. Domestic sewage
Answer» A. Paints
Explanation: Heavy metals (cadmium, cobalt, chromium, copper, mercury, manganese, nickel, lead, zinc, molybdenum, tin) are among the main pollutants. Industrial paints are loaded with metals such as lead, calcium, cadmium and other such chemicals, When any amount of paint is ledoff into the water bodies it causes water pollution by causing the amount of heavy metals present in water to fluctuate, Each one of these has severe toxic effects on living beings, and tend to accumulate in aquatic food chains.

Nitrogen forms a variety of compounds in all oxidation states ranging from -

A. -3 to + 5
B. -3 to +3
C. -3 to + 4
D. -3 to +6
Answer» A. -3 to + 5
Explanation: Nitrogen compounds are chemical compounds containing nitrogen ions. Nitrogen forms compounds with a wide range of oxidation states that range from -3 for the nitride ion to in nitrates and nitric acid. +5 oxidation state compounds are strong oxidizing agents. -3 oxidation state compounds are weak reducing agents.

The next higher homologue of C6H14 is -

A. C6H14
B. C7H12
C. C6H12
D. C7H16
Answer» D. C7H16
Explanation: In chemistry, a homologous series is a series of compounds with a similar general formula, possessing similar chemical properties due to the presence of the same functional group. C6H14 stands for Hexane which is an alkane with six carbon atoms. In the alkane homologous series, each member differs from the previous one by a CH2 group (or 14 atomic mass units). The CH2 group is called Methylene Group. So the higher homologue of Hexane is Heptane (C7H16).

Biogas majorly contains -

A. Ethane
B. Methane
C. Hydrogen
Answer» B. Methane
Explanation: Biogas is a mixture of different gases, major portion in biogas being methane (CH4) and carbon dioxide (CO2). It also contains traces of other gases like hydrogen (H2), Moisture (H2O) , hydrogen sulfide (H2S) etc.

The sewage obtained from water closets and urinals is known as –

A. Sanitary waste
B. Industrial waste
C. Garbage
D. Sullage
Answer» A. Sanitary waste
Explanation: The sewage obtained from water closets and urinals in known as Sanitary waste.

In organic compounds, nitrogen is estimated by –

A. Carius method
B. Victor-Meyees method
C. Liebigs method
D. Dumas' method
Answer» D. Dumas' method
Explanation: In Dumas' method, a known quantity of nitrogen containing organic compound is heated strongly with excess of copper oxide in an atmosphere of carbon dioxide to produce free nitrogen in addition to carbon dioxide and water.

The hottest part of the gas flame is known as –

A. blue zone
B. non-luminous zone
C. luminous zone
D. dark zone
Answer» C. luminous zone
Explanation: 0

What is dry ice?

A. Solid Carbon dioxide
B. Solid Nitrogen dioxide
C. Solid Sulphur dioxide
D. Solid Water
Answer» A. Solid Carbon dioxide
Explanation: Dry ice, sometimes referred to as "cardice," is the solid form of carbon dioxide. Its advantages include lower temperature than that of water ice and not leaving any residue (other than incidental frost from moisture in the atmosphere).

Threshold limit value of copper in the atmospheric air is -

A. 0.001 mg/m3
B. 0.01 mg/m3
C. 1.0 mg/m3
D. 5.0 mg/m3
Answer» C. 1.0 mg/m3
Explanation: Inspirable copper dust takes a predominantly fibrous effect. The ALV of copper aerosol in the workplace atmosphere is 0.5 mg/m3, while the threshold limit value (TLV) is 1.0 mg/m3.

Silicone is a polymer of –

A. Tetraalkyl silane
B. Silicon tetrachloride
C. Dialkyl dichloro silane
D. Silane
Answer» C. Dialkyl dichloro silane
Explanation: In order to manufacture silicones, alkyl-substituted chlorosilanes are used as starting material. Since dimethylsilane contains —OH group at the end of the chain,polymerization and chain length increases. However, the hydrolysis of alkyl trichlorosilane gives very complex cross linked polymer.

Which is not an anasthetic agent in surgical operations?

A. Chloroform
B. Ether
C. Nitrous oxide
D. Acetone
Answer» D. Acetone
Explanation: The currently used inhalational anaesthetic agents are mainly: nitrous oxide, isoflurane, sevoflurane and desflurane. Chloroform, ether, ethylene are other an- aesthetic agents. However, they are not widely used in clinical practice today.

Brass is an alloy of :

A. Cu, Al and Zn
B. Cu and Sn
C. Cu and Zn
D. Al and Mg
Answer» C. Cu and Zn
Explanation: Brass is an alloy made of copper and zinc. The proportions of zinc and copper can be varied to cre-ate a range of brasses with varying properties. By comparison, bronze is principally an alloy of copper and tin.

Iron is prevented from rusting by coating with zinc. This process is called as –

A. Galvanisation
B. Corrosion
C. Sublimation
D. Reduction
Answer» A. Galvanisation
Explanation: Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electro-deposition processes, the most common method in current use is hot-dip galvanization, in which steel parts are sub-merged in a bath of molten zinc.

Which of the following is the maximum number of electrons that can be present in M- shell?

A. 2
B. 8
C. 18
D. 32
Answer» C. 18
Explanation: The maximum number of electrons that can occupy a specific energy level can be found using the following formula: Electron Capacity = 2n2. The variable n represents the Principal Quantum Number, the number of the energy level in question.

Chemical that is used in photography -

A. Copper sulphate
B. Silver bromide
C. Magnesium sulphate
D. None
Answer» B. Silver bromide
Explanation: Silver bromide (AgBr) is a soft pale-yellow, water insoluble salt well for its unusual sensitivity to light. This property has allowed silver halides to become the basis of modern photographic materials.

Sodium Carbonate is commonly known as -

A. Baking Soda
B. Washing Soda
C. Caustic Soda
D. Caustic Potash
Answer» B. Washing Soda
Explanation: Sodium carbonate (Na2CO3) is also known as washing soda, soda ash and soda crystals. It is a salt of carbonic acid, a chemical that produces a wide range of salts collectively known as carbonates. It can be used to remove stubborn stains from laundry.

When a bond is formed between two atoms, the energy of the sys-tem will –

A. increase
B. decrease
C. remain the same
D. may increase or decrease
Answer» C. remain the same
Explanation: The fundamental reason for the bonding of atoms is that they lose their stored potential energy by forming bonds. This is the only reason for chemical combination. So, when a bond is formed between two atoms, stored potential enemy is always released to the surroundings.

The ore of Aluminium is -

A. Fluorspar
B. Bauxite
C. Chalco pyrites
D. Hematite
Answer» B. Bauxite
Explanation: Bauxite, an aluminium ore, is the world's main source of aluminium. Bauxite is priinarily comprised of aluminum oxide compounds (alumina), silica, iron oxides and titanium dioxide. It is refined through the Bayer chemical process into alumina.

Which of the following molecules or ions involved in the Nitrogen Cycle do not contain oxygen atom?

A. Nitrite
B. Ammonia
C. Nitrate
D. Laughing gas
Answer» B. Ammonia
Explanation: 0

Which of the following is used as a coolant in nuclear reactors?

A. Heavy water
B. Cadmium
C. Liquid sodium
D. Graphite
Answer» C. Liquid sodium
Explanation: Liquid metallic sodium may be used as the sole coolant, carrying heat from the core. Sodium has only one stable isotope, sodium-23. Sodium-23 is a very weak absorber of neutrons.
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