Chemistry Questions and Answers for Competitive Exam

Chemistry questions and answers are the most important study material who are preparing for upcoming competitive exams/entranvce exams such as RRB, SSC, PSC, Bank, GATE, CAT, UPSC, PSU, Defence and many more. In this article, we sharing Chemistry Question and answers for Students who are preparing for Competitive examinations Like Railway NTPC, Group D, Patwari, Police Exams.

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Chemistry GK MCQs

Q.1. The chemical used as a fixer in photography is ?

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(a) sodium thiosulphate
(b) sodium sulphate
(c) borax
(d) ammonium sulphate

Ans .  A

Q.2. Water drops are spherical because of ?

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(a) viscosity
(b) density
(c) polarity
(d) surface tension

Ans .  D

Q.3. Aspirin is

(a) acetyl salicylic acid
(b) sodium salicylate
(c) methyl salicylate
(d) ethyl salicylate

Ans .  A

Q.4. The oxide of Nitrogen used in medicine as anaesthetic is ?

(a) Nitrogen pentoxide
(b) Nitrous oxide
(c) Nitric oxide
(d) Nitrogen dioxide

Ans .  A

Q.5. Which one of the following metals does not react with water to produce Hydrogen?

(a) Cadmium
(b) Lithium
(c) Potassium
(d) Sodium

Ans .  A

Q.6. The most electronegative element among the following is

(a) sodium
(b) bromine
(c) fluorine
(d) oxygen

Ans .  C

Q.7. Atomic number is equal to

(a) Number of electrons
(b) Number of nutron
(c) Number of protons
(d) Total number of protons and neutrons

Ans .  C

Q.8. The cathode of a lead storage battery is made up of

(a) Zinc
(b) Lead oxide
(c) Manganese dioxide
(d) Lead

Ans .  D

Q.9. Vinegar is trade name of

(a) Acetic acid
(b) Chloroform
(c) Ethyl alcohol
(d) Carbon tetrachloride

Ans .  A

Q.10. Which of the following elements behave chemically both as metal and non metal?

(a) Boron
(b) Argon
(c) Carbon
(d) Xenon

Ans .  A

Objective Type Chemistry Competitive Exams Questions

Q.1. Nail polish remover contains

(a) Acetone
(b) Benzeme
(c) Petroleum ether
(d) Acetic acid

Ans .  A

Q.2. Which one of the following correctly defines the state of glass?

(a) Crystalline solid
(b) Super cooled liquid
(c) Condensed gas
(d) Liquid crystal

Ans .  B

Q.3. Which one of the following is an element which never exhibits positive oxidation state in any of its compounds?

(a) Oxygen
(b) Chlorine
(c) Fluorine
(d) Carbon

Ans .  C

Q.4. Which one of the following materials is suitable for water purification?

(a) Silicones
(b) Zeolites
(c) Asbestos
(d) Quartz

Ans .  B

Q.5. Which one of the following is a major constituent of Biogas ?

(a) Carbon dioxide
(b) methane
(c) hydrogen
(d) nitrogen dioxide

Ans .  B

Q.6. Which one of the following is present in the emission from “unleaded petrol”?

(a) carbon monoxide
(b) carbon dioxide
(c) ethylene
(d) hydrocarbons

Ans .  D

Q.7. Which one of the following is used in preparing match sticks?

(a) Chile saltpeter
(b) Indian salpetre
(c) Red phosphorus
(d) Sodium bicarbonate

Ans .  C

Q.8. In which of the following cases, components can be separated using a separating funnel?

(a) Mixture of acetone and water
(b) Mixture of oil and water
(c) Different gases in the air
(d) None of the above

Ans .  B

Q.9. Choose the incorrect statement:

(a) Epsom salt is an ore containing Sodium
(b) Bauxite is an ore of Aluminium
(c) Asbestos is an ore containing Calcium
(d) Milarite mineral contains Nickel

Ans .  A

Q.10. Which of the following is the purest form of Iron?

(a) Pig iron
(b) Cast iron
(c) Wrought iron
(d) None of the above

Ans .  C

Chemistry Questions with Answers

Q.1 The metal does not give H2 on treatment with dilute HCL is

(A) Zn

(B) Fe

(C) Ag

(D) Ca

Ans .  C

Q.2 The number of g-molecule of oxygen in 6.02 x 1024CO molecules is

(A) 1 gram of molecule

(B) 0.5 gram of molecule

(C) 5 gram of molecule

(D) 10 gram of molecule

Ans .  C

Q.3 The most extensive, commercially useful source of thorium as monazite sand occurs in India at

(A) Orissa coast

(B) Travancore coast

(C) West Bengal coast

(D) Gujarat coast

Ans .  B

Q.4 The main active constituent of tea and coffee is

(A) nicotine

(B) chlorophyll

(C) caffeine

(D) aspirin

Ans .  C

Q.5 The maximum number of isomers for an alkene with molecular formula C4H8 is

(A) 5

(B) 4

(C) 2

(D) 3

Ans .  B

Q.6 The hardest form of carbon is

(A) coke

(B) graphite

(C) diamond

(D) charcoal

Ans .  C

Q.7 The most important ore of aluminum is

(A) bauxite

(B) magnetite

(C) haematite

(D) monazite

Ans .  A

Q.8 The organic reaction represented by equation CH3 – CH = O + H2NOH gives CH3 – CH – NH + H2O is an example of

(A) an addition reaction

(B) a condensation reaction

(C) an oxidation reaction

(D) an elimination reaction

Ans .  B

Q.9 The number of electrons presents in H+ is

(A) zero

(B) one

(C) two

(D) three

Ans .  A

Q.10 The hottest part of the gas flame is known as

(A) luminous zone

(B) dark zone

(C) blue zone

(D) non-luminous zone

Ans .  D

Q.11 The human body is made up of several chemical elements; the element present in the highest proportion (65%) in the body is

(A) carbon

(B) hydrogen

(C) oxygen

(D) nitrogen

Ans .  C

Q.12 The isomerism which exists between CH3CHCI2 and CH2CI. CH2CI is

(A) chain isomerism

(B) functional group isomerism

(C) positional isomerism

(D) metamerism

Ans .  C

Q.13 The half-life period of an isotope is 2 hours. After 6 hours what fraction of the initial quantity of the isotope will be left behind?

(A) 1/6

(B) 1/3

(C) 1/8

(D) 1/4

Ans .  C

Q.14 The number of waves made by an electron moving in an orbit having maximum magnetic quantum number is +3

(A) 4

(B) 5

(C) 2

(D) zero

Ans .  A

Q.15 The number of atoms present in 21.6 gram of silver (atomic weight = 108) is the same as the molecules in

(A) 1.8 gram of H2O

(B) 12 moles of KMnO4

(C) 0.6N H2SO4

(D) 4.6 gram of C2H5OH

Ans .  B

Q.16 The National Chemical Laboratory is situated in

(A) New Delhi

(B) Bangalore

(C) Pune

(D) Patna

Ans .  C

Q.17 Equal masses of oxygen, hydrogen, and methane are kept under identical conditions. The ratio of the volumes of gases will be

(A) 2 : 16 : 2

(B) 2 : 16 : 1

(C) 1 : 16 : 2

(D) 1 : 1 : 1

Ans .  C

Q.18 The mass number of an atom is equal to

(A) the number of protons

(B) the number of protons and electrons

(C) the number of nucleons

(D) the number of neutrons

Ans .  C

Q.19 The high reactivity of fluorine is due to

(A) its high electronegativity

(B) small size of fluorine atom

(C) availability of d-orbitals

(D) strong F – F bond

Ans .  A

Q.20 The iron ore magnetite consists of

(A) Fe2O3

(B) Fe3OH4

(C) FeCO3

(D) 3Fe2O3 .. 3H2O

Ans .  A

Q.21 The ionization energy of the hydrogen atom in the ground state is x KJ. The energy required for an electron to jump from 2nd orbit to 3rd orbit is

(A) 5x/36

(B) 5x

(C) 7.2 x

(D) x/6

Ans .  A

Q.22 The major constituent of air is

(A) nitrogen

(B) carbon dioxide

(C) oxygen

(D) hydrogen

Ans .  A

Q.23 The main chemical constituent of clay is

(A) silicon oxide

(B) aluminium borosilicate

(C) zeolites

(D) aluminium silicate

Ans .  D

Q.24 The mineral containing both magnesium and calcium is

(A) magnesite

(B) calcite

(C) carnallite

(D) dolomite

Ans .  D

Q.25 The method that cannot be used for removing the permanent hardness of water is

(A) adding sodium carbonate

(B) distillation

(C) adding caustic soda

(D) boiling

Ans .  D

Q.26 The following are the half-lives of four active isotopes. Which one of the following is the most dangerous to handle?

(A) 3 billion years

(B) 100 years

(C) 0.01 minute

(D) 13 days

Ans .  C

Q.27 The gas used for artificial ripening of green fruit is

(A) ethylene

(B) ethane

(C) carbon dioxide

(D) acetylene

Ans .  A

Q.28 Zone refining is used for the purification of

(A) Au

(B) Ge

(C) Ag

(D) Cu

Ans .  B

Q.29 The main chemical constituent of the oil of cardamom which is responsible for flavor of this oil is

(A) cineole

(B) engenol

(C) geraniol

(D) limonene

Ans .  A

Q.30 The molecule which has the highest percentage of ionic character among the following is

(A) HI

(B) HF


(D) HBr

Ans .  B

Q.31 The gas used in the manufacture of vanaspati from vegetable oil is

(A) hydrogen

(B) oxygen

(C) nitrogen

(D) carbon dioxide

Ans .  A

Q.32 The ionic radii of N3-, O2-, F- and Na+ follows the order

(A) N3- > O2- > F- > Na+

(B) N3- > Na+ > O2- > F-

(C) Na+ > O2- > N3- > F-

(D) O2- > F- > Na+ > N3-

Ans .  A

Q.33 The graphite rods in the nuclear reactor

(A) react with U to release energy

(B) produce neutrons

(C) undergo combustion which triggers the nuclear fission

(D) convert fast moving neutrons into thermal neutrons

Ans .  D

Q.34 The first metal used by man was

(A) iron

(B) copper

(C) gold

(D) bronze

Ans .  B

Q.35 The hydronium ion is

(A) H+

(B) HO –

(C) H2+

(D) H3O+

Ans .  D

Q.36 The most electropositive elements among the following is

(A) Na

(B) Ca

(C) K

(D) Cs

Ans .  D

Q.37 The number of waves in n x 10th Bohr’s orbit is

(A) n2

(B) n

(C) n-2

(D) n3

Ans .  B

Q.38 The mass of one Avogadro number of helium atom is

(A) 1.00 gram

(B) 4.00 gram

(C) 8.00 gram

(D) 4 x 6.02 x 1023 gram

Ans .  B

Q.39 The items amenable to detection by soft x-rays are

(A) contrabands

(B) lead in bullets

(C) narcotics

(D) genuine coins from counterfeit coins

Ans .  D

Q.40 The material which can be deformed permanently by heat and pressure is called a

(A) thermoplastic

(B) thermoset

(C) chemical compound

(D) polymer

Ans .  B

Q.41 The mass number of a nucleus is

(A) always less than its atomic number

(B) the sum of the number of protons and neutrons present in the nucleus

(C) always more than the atomic weight

(D) a fraction

Ans .  B

Q.42 The inexpensive and commonly used variety of glass is called soda glass. It is called so because

(A) was used initially for making bottles of soda(carbonated drink)

(B) is made using soda(sodium carbonate)

(C) was initially used for storing sodium carbonate

(D) is made using soda lime

Ans .  B

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