1. The material used for electric fuse is an alloy of tin and lead. This alloy should have:

A. high specific resistance and low melting point. B. low specific resistance and high melting point C. low specific resistance and low melting point D. high specific resistance and high melting point.

Answer - Option A
Explanation -
The material should have high specific value and low melting point which is used for electric fuse is an alloy of tin and lead.
2. Silver ware turns black after a period of time due to formation of :

A. nitrate coating on silver B. sulphide coating on silver. C. chloride coating on silver. D. oxide coating on silver

Answer - Option B
Explanation -
Silver converts into silver sulphide in presence of air and [latex]{H}_{2}[/latex]S, which is black in colour
2Ag +[latex]{H}_{2}[/latex]S → [latex]{{Ag}_{2}}_{Black}[/latex]S + [latex]{2H}^{+}[/latex]
3. When concentrated [latex]{H}_{2} {SO}_{4}[/latex] spilts on the surface, it should be immediately cleaned :

A. with a piece of cloth. B. by adding cold water C. by adding solid [latex]{Na}_{2} {CO}_{3}[/latex] D.by adding solid BaC[latex]{l}_{2}[/latex]

Answer - Option D
Explanation -
When concentrated [latex]{H}_{2} {SO}_{4}[/latex] splits on the surface it should be immediately cleaned by adding solid BaC[latex]{l}_{2}[/latex] (Barium Chloride).
4. A bee-sitting leaves an acid which causes pain and irritation. The injected acid is :

A. acetic acid. B. sulphuric acid. C. citric acid. D. methanoic acid

Answer - Option D
Explanation -
A bee-sting leaves methanoic acid (HCOOH) which causes pain and irritation.
5. Iron nails are dipped into blue copper sulphate solution. After some time iron nails are :

A. dissolved and blue colour is discharged B. dissolved but blue colour is not discharged. C. not dissolved and blue colour is not discharged. D. not dissolved but blue colour is discharged.

Answer - Option D
Explanation -
Iron is more reactive than copper, so replace copper from copper sulphate solution.
Fe + Cu[latex]{{SO}_{4}}_{Blue} → Fe{{SO}_{4}}_{Green} + {CU}_{Reddish brown}[/latex]
Copper submitted on iron nails by which the colour of solution become light.
6. A student by chance mixed acetone with alcohol. This mixture of acetone and alcohol can be separated by :

A. filtration B. separating funnel. C. fractional crystallization D. fractional distillation.

Answer - Option D
Explanation -
Acetone and alcohol have different boiling points so it can be separated by fractional distillation.
7. Which one among the following methods is not effective in removing arsenic from contaminated ground water ?

A. Boiling B. Reverse osmosis C. Ion exchange D. Coagulation-adsorption

Answer - Option A
8. Which one among the following is the main ingredient in cement?

A. Gypsum B. Lime stone C. Clay D. Ash

Answer - Option B
9. Glass is actually :

A. a crystalline solid. B. an ionic solid C. an elastic solid D. a vitrified liquid

Answer - Option C
Explanation -
Glass is an elastic solid.
10. Solutions in test tubes containing [latex]{H}_{2}O[/latex] and aqueous NaOH can be differentiated with the help of :

A. red litmus. B. blue litmus C. [latex]{Na}_{2} {CO}_{3}[/latex] D. HCl (aqueous)

Answer - Option A
Explanation -
Red litmus is unaffected by water ([latex]{H}_{2}O[/latex]) because it is neutral in nature while NaOH is basic in nature so red litmus turns into blue colour.
11. Human stomach produces acid ‘X' which helps in digestion of food. Acid ‘X' is :

A. acetic acid. B. methanoic acid. C. hydrochloric acid. D. citric acid.

Answer - Option C
Explanation -
Human stomach produces Hydrochloric (Hcl) which helps in digestion of food.
12. 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 - Option C
Explanation -
Heavy water is used as moderator in nuclear reactors which reduces the velocity of neutrons.
13. Which one of the following contains maximum percentage of nitrogen by mass?

A. Urea B. Ammonium cyanide C. Ammonium carbonate D. Ammonium nitrate

Answer - Option B
Explanation -
Percentage of Nitrogen = [latex]\frac{28}{60}[/latex] * 100 = 46.6%
In Ammonium Cyanide (N[latex]{H}_{4}[/latex]CN)
Percentage of Nitrogen = [latex]\frac{28}{44}[/latex] * 100 = 63.6%
In Ammonium Carbonate [latex]{(NH{H}_{4})}_{2}{CO}_{3}[/latex]
Percentage of Nitrogen = [latex]\frac{28}{96}[/latex] * 100 = 29.2%
In Ammonium nitrate [latex]{(NH{H}_{4})}_{2}{NO}_{3}[/latex]
Percentage of Nitrogen = [latex]\frac{28}{98}[/latex] *100 = 42.8%
So, in ammonium cyanide percentage of nitrogen is maximum
14. Oxygen and ozone are

A. Allotropes B. isomers C. isotopes D. isobars

Answer - Option A
Explanation -
Oxygen ([latex]{O}_{2}[/latex]) and ozone ([latex]{O}_{3}[/latex]) are allotropic forms of oxygen.
15. When applied to the affected area, which one of the following will relieve the pain due to ant-bite or bee-sting?

A. Lemon juice B. Vinegar C. Baking soda D. Caustic soda

Answer - Option C
Explanation - In ant bite and bee sting formic acid (HCOOH) is present , which is responsible for pain and irritation. Formic acid is a weak acid it can be neutral so baking soda (sodium bi-carbonate[latex]{Na}_{2} {CO}_{3}[/latex] ) is used in relieve in pain due to anti-bite or bee sting.

1. Hadrons and Baryons are

A. Industrial chemicals B. Types of subatomic particles C. Alkalies D. Cyclotrons

Answer - Option B
Explanation -
Hadrons and Baryons are types of subatomic particles. Baryons are heavy subatomic particles that are made up of three quarks.
2. Which of the following is a heterogeneous mixture?

A. Brass B. Sugar solution in water C. Air D. Milk

Answer - Option D
Explanation -
Milk is an example of a heterogeneous mixture. Mixtures can be separated into two (or more) individual substances by physical means. Our glass of ice water is a mixture because we can easily separate the ice from the liquid water by filtration
3. A class of compounds which are used as fragrances when molecular weight is low and are naturally occurring fats when molecular weight is high in the series, is called

A. amino acids B. aromatic compounds C. esters D. organic acids

Answer - Option C
Explanation - A class of compounds which are used as fragrances when molecular weight is low and are naturally occurring fats when molecular weight is high in the series, is called esters.
4. Disinfection of drinking water is done to remove:

A. Odour B. Bacterias C. Turbidity D. Colour

Answer - Option B
Explanation -
Disinfection of drinking water is done to remove Bacteria. Water disinfection means the removal, deactivation or killing of pathogenic microorganisms.
Microorganisms are destroyed or deactivated, resulting in termination of growth and reproduction. When microorganisms are not removed from drinking water, drinking water usage will cause people to fall ill.
5. Global warming is caused by :

A. [latex]{N}_{2}[/latex] B. [latex]{CO}_{2}[/latex] C. Ozone D. None of these

Answer - Option B
Explanation -
[latex]{CO}_{2}[/latex] causes green house effect trading to global warming.
6. What is the General formula of Alkanes ?

A. [latex]{C}_{n}{H}_{2n + 2}[/latex] B. [latex]{C}_{n}{H}_{2n}[/latex] C. [latex]{C}_{n}{H}_{2n - 2}[/latex] D. [latex]{C}_{n}{H}_{2n + 4}[/latex]

Answer - Option A
Explanation -
The alkanes comprise a series of compounds that are composed of carbon and hydrogen atoms with single covalent bonds. This group of compounds comprises a homologous series with a general molecular formula of [latex]{C}_{n}{H}_{2n + 2}[/latex].
7. The pollutant responsible for ozone holes is :

A. [latex]{CO}_{2}[/latex] B. CO C. [latex]{SO}_{2}[/latex] D. CFC

Answer - Option B
Explanation - Chlorofluorocarbons (CFCs) and other halogenated ozone depleting substances (ODS) are mainly responsible for man-made chemical ozone depletion. The total amount of effective halogens (chlorine and bromine) in the stratosphere can be calculated and are known as the equivalent effective stratospheric chlorine (EESC).
8. Ammonia is prepared commercially by the :

A. Oswald process B. Hall process C. Contact process D. Haber process

Answer - Option D
Explanation -
The Haber Process combines nitrogen from the air with hydrogen derived mainly from natural gas (methane) into ammonia. The reaction is reversible and the production of ammonia is exothermic. The catalyst is actually slightly more complicated than pure iron.
9. The elements which have same mass number but different atomic numbers are know as :

A. Isotones B. Isobars C. Isotopes D. Halogens

Answer - Option B
Explanation -
Atoms of chemical elements having same atomic mass but a different atomic number are called Isobars. The sum of the number of protons and neutrons together form the atomic mass.
10. Which one of the following is not a Noble Gas ?

A. Helium B. Bromine C. Argon D. Neon

Answer - Option C
Explanation - Among the given options, Bromine is not a Noble Gas.The six noble gases that occur naturally are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn).
11. Major contributing activity towards Global Warming by Greenhouse gases

A. Agriculture B. Deforestation C. Energy D. lndustry

Answer - Option A
Explanation - A greenhouse gas is a gas that absorbs and emits radiant energy within the thermal infrared range. Increasing greenhouse gas emissions cause the greenhouse effect.
12. Electrostatic Precipitators are devices for

A. Particulate Emission Control B. Water Pollution Control C. Noise Pollution Control D. Energy Pollution Control

Answer - Option A
Explanation -
Electrostatic Precipitators are devices for particulate emission control.
13. Biochemical Oxygen Demand (BOD) is a measure of

A. Oxygen utilized during oxidation of organic matters B. Suspended particles in water C. Suspended particles in air D. Noise level in air

Answer - Option C
Explanation -
Biochemical Oxygen Demand (BOD, also called Biological Oxygen Demand) is the amount of dissolved oxygen needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period. The BOD value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 °C. Biochemical Oxygen Demand (BOD) is a measure of Oxygen utilized during oxidation of organic matters.
14. Biodegradable pollutants are

A. quickly degraded by natural means B. can not be degraded C. can be degraded by burning only D. disposed in flowing water only

Answer - Option A
Explanation -
Biodegradable pollutants are quickly degraded by natural means. Biodegradable pollutants: Such pollutants are quickly degraded by microbes (bacteria and fungi) in nature e.g. sewage, ...
Examples of such pollutants are: DDT, mercury, lead, arsenic, some pesticides, radioactive substances, glass, plastic, aluminium pieces, etc
15. The state in which molecular attractions are very strong is

A. Solid B. Liquid C. Gas D. Vapour

Answer - Option D
Explanation -
Solid has the highest molecular attractions hence is dense and compact.

1. What is the common property between LiAlH4, Sodium amalgam and NaB[latex]{H}_{4}[/latex]?

A. They are used in removing slag from molten metals B. They are used in manufacturing esters C. They are reducing agents D. They are coated on welding electrodes

Answer - Option A
Explanation -
In organic chemistry we normally learn about two important reducing reagents, sodium borohydride (NaB[latex]{H}_{4}[/latex]) and lithium aluminum hydride (LiAl[latex]{H}_{4}[/latex] or LAH). We learn that NaB[latex]{H}_{4}[/latex] is a “weak reducing agent” and can only take aldehydes and ketones to alcohols easily. NaB[latex]{H}_{4}[/latex] can handle esters, but it is very slow at converting them and thus not preferable.
2. Soaps are manufactured by:

A. Reaction of alkalies with glycerol B. Reaction of fats with soluble hydroxides C. Reaction of calcium and magnesium ions with dilute sulphuric acid D. Reaction of dodecyl benzene with [latex]{H}_{2}{SO}_{4}[/latex] and then NaOH

Answer - Option B
Explanation -
Fats and oils are composed of triglycerides; three molecules of fatty acids attach to a single molecule of glycerol. The alkaline solution, which is often called lye (although the term “lye soap” refers almost exclusively to soaps made with sodium hydroxide), brings about a chemical reaction known as saponification.
3. Chemical bonding which results in formation of molecules from atoms is basically-

A. Nuclear force B. Short range forces C. Electrostatic force D. Gravitational force

Answer - Option C
Explanation -
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.
4. Glycerol can be represented by chemical formula:

A. [latex]{C}_{2}H{SO}_{2}[/latex] B. [latex]{C}_{3}{H}_{7}OH[/latex] C. [latex]{C}_{3}{H}_{5}OH[/latex] D. [latex]{C}_{3}{H}_{8}{O}_{3}[/latex]

Answer - Option D
Explanation -
The glycerol chemical formula is [latex]{C}_{3}{H}_{8}{O}_{3}[/latex] and its extended formula is [latex]C{H}_{2}OH-CHOH-C{H}_{2}OH.[/latex] The IUPAC name for glycerol is 1, 2, 3- Trihydroxypropane or 1, 2, 3- Propanetriol.
5. The most ideal disinfectant used for drinking water is :

A. Alum B. Chlorine C. Lime D. Nitrogen

Answer - Option B
Explanation -
The most ideal disinfectant used for drinking water is Chlorine. Chlorine is one of the most commonly used disinfectants for water disinfection.
6. Which one of the following is generally added to Table Salt to make it flow freely in rainy season ?

A. [latex]{Ca}_{3}{({PO}_{4})}_{2}[/latex] B. [latex]{Na}_{3}{PO}_{4}[/latex] C. KCI D. KI

Answer - Option A
Explanation -
[latex]{Ca}_{3}{({PO}_{4})}_{2}[/latex] is generally added to Table Salt to make it flow freely in rainy season.
7. Valence electrons in the element A are 3 and that in element B are 6. Most probable compound formed from A and B is :

A. [latex]{A}_{2}B[/latex] B. [latex]A{B}_{2}[/latex] C. [latex]{A}_{2}{B}_{3}[/latex] D. [latex]{A}_{3}{B}_{2}[/latex]

Answer - Option B
Explanation -
Valence electrons in the element A are 3 and that in element B are 6. Most probable compound formed from A and B is [latex]{A}_{2}{B}_{3}[/latex]
8. Atoms of the elements belonging to the same group of periodic table will have :

A. Same number of protons B. Same number of neutrons C. Same number of electrons D. Same number of electrons in the valence shell

Answer - Option D
Explanation -
Atoms of the elements belonging to the same group of periodic table will have Same number of electrons in the valence shell.
9. Avogadro's number, [latex]{N}_{A}[/latex] means

A. number of protons in nucleus of an atom B. number of atoms in one gram atom of an element C. sum of the number of protons and the neutrons in the nucleus of an atom D. number of protons or electrons in one gram of Sodium

Answer - Option B
Explanation -
In chemistry and physics, the Avogadro constant, named after scientist Amedeo Avogadro, is the number of constituent particles, usually atoms or molecules, that are contained in the amount of substance given by one mole.
10. Isotopes of the same element have

A. Same number of neutrons B. Same atomic mass C. Same number of protons D. Different atomic number

Answer - Option C
Explanation -
The atoms of a chemical element can exist in different types. These are called isotopes. They have the same number of protons (and electrons), but different numbers of neutrons. Different isotopes of the same element have different masses.
11. In a reaction between Zinc and Iodine. Zinc Iodide is formed. What is being oxidized ?

A. Zinc ions B. Iodide ions C. Zinc Atom D. Iodine

Answer - Option A
Explanation -
Zinc powder is added to a solution of iodine in ethanol. An exothermic red-ox reaction occurs, forming zinc iodide, which can be obtained by evaporating the solvent. In reaction between Zinc and Iodine. Zinc Iodide is formed. Zinc atom is being oxidized.
12. Which of t he following halogens is t he best oxidizing agent ?

A. [latex]{F}_{2}[/latex] B. [latex]{Cl}_{2}[/latex] C. [latex]{Br}_{2}[/latex] D. [latex]{I}_{2}[/latex]

Answer - Option A
Explanation -
Fluorine is such a powerful oxidizing agent that you can’t reasonably do solution reactions with it.
13. Nitrogen is used to fill electric bulbs because it

A. is lighter than air B. makes the bulb to give more light C. does not support combustion D. is non-toxic

Answer - Option C
Explanation -
Filling a bulb with an inert gas such as argon or nitrogen slows down the evaporation of the tungsten filament compared to operating it in a vacuum. This allows for greater temperatures and therefore greater efficacy with less reduction in filament life.
14. Froth flotation process for the concentration of Ores is an illustration of the practical application of

A. Adsorption B. Absorption C. Coagulation D. Sedimentation

Answer - Option A
Explanation -
Froth flotation process for the concentration of Ores is an illustration of the practical application of Adsorption.
15. The presence of nitrogen in the products of combustion ensures that

A. Complete combustion of fuel takes place B. Incomplete combustion of fuel takes place C. dry products of combustion are analysed D. air is used for the combustion

Answer - Option D
Explanation -
The presence of nitrogen in the products of combustion ensures that air is used for the combustion.