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Atomic Structure MCQs

Question 1. The smallest part of an element that retains the chemical properties of the element is
(1) Electron
(2) Molecule
(3) Atom
(4) Proton

Answer: (4) Proton

Question 2. Electron was discovered by
(1) William Crookes
(2) A. Arrhenius
(3) Michael Faraday
(4) J. J. Thomson

Answer: (4) J. J. Thomson

Question 3. Cathode rays are composed of
(1) Radiation
(2) Thermal radiation
(3) Beam of negatively charged particles
(4) Positively charged particles

Answer: (3) Beam of negatively charged particles

Question 4. Cathode rays are deflected under the influence of electromagnetic fields because cathode rays are
(1) Electromagnetic radiation (EMR, i-e., light)
(2) Positively charged particles
(3) Beam of neutral particles
(4) Beam of electrons

Answer: (4) Beam of electrons

Question 5. In a perforated cathode ray tube, other rays other than cathode rays were found. These rays are
(1) Protons
(2) Electrons
(3) Radiation
(4) Neutrons

Answer: (3) Radiation

Question 6. Who among the following got Nobel Prize twice?
(1) Rutherford
(2) Bohr
(3) Einstein
(4) Marie Curie

Answer: (4) Marie Curie

Question 7. Radioactivity was discovered by
(1) Rutherford
(2) Becquerel
(3) Marie Curie
(4) Pierre Curie

Answer: (3) Marie Curie

Question 8. Radioactivity was first recognised while working with which element?
(1) Uranium
(2) Thorium
(3) Polonium
(4) Barium

Answer: (1) Uranium

Question 9. The concept of nucleus of an atom was given by
(1) J. J. Thomson
(2) Neils Bohr
(3) Rutherford
(4) M. Curie

Answer: (3) Rutherford

Question 10. The diameter of the nucleus is of the order of
(1)10^–3cm
(2) 10^–23cm
(3) 10^–3 cm
(4) 10^–13 cm

Answer: (4) 10^–13 cm

Question 11. From the fact that a helium atom is four times as heavy as a. hydrogen atom, Rutherford predicted the existence of
(1) Proton
(2) Isotope
(3) Neutron
(4) Nucleus

Answer: (1) Proton

Question 12. From the study of sun spectra, the element first identified is
(1) Helium
(2) Hydrogen
(3) Uranium
(4) Gold

Answer: (1) Helium

Question 13. Which of the following concepts is not connected to Bohr’s model?
(1) Circular shell or orbit
(2) Quantization
(3) Line spectra of hydrogen
(4) Nuclear force

Answer: (2) Quantization

Question 14. An electron in a Bohr’s orbit is associated with definite
(1) Radius
(2) Velocity
(3) Energy
(4) All of the above

Answer: (3) Energy

Question 15. lonization energy of hydrogen atom, as calculated (by Bohr) and experimentally obtained, is
(1) 13.56 eV
(2) 13.56 J
(3) 13.56 Cal
(4) None of these

Answer: (1) 13.56 eV

Question 16. Which of the following is considered as a limitation of Bohr’s model? It wa unable to explain
(1) E_{n ,} ie., energy of the nth shell electron of hydrogen
(2) Ionization energy of hydrogen
(3) Line spectrum of helium
(4) Line spectrum of hydrogen

Answer: (2) lonization energy of hydrogen

Question 17. On which of the following, Rutherford’s model differs from Bohr’s model?
(1) Circular shape of orbit
(2) Concept of the nucleus
(3) Empty space in an atom
(4) Stability of an atom

Answer: (4) Stability of an atom

Question 18. Which of the following is true?
(A = mass number, Z = atomic number, N = number of neutrons)
(1) A= Z
(2) A=Z-N
(3) A=Z+N
(4) A=N-Z

Answer: (3) A=Z+N

Question 19. Isotopes of an element have the same
(1) Mass number (A)
(2) Number of neutrons
(3) Number of protons
(4) Number of protons but not electrons

Answer: (3) Number of protons

Question 20. Isotopes are atoms with same number of
(1) Neutrons
(2) Protons
(3) Electrons
(4) Protons

Answer: (1) Neutrons

Question 21. Isobars are atoms having same number of
(1) Protons
(2) Nettvons
(3) Electrons
(4) Protons + Neutrons

Answer: (4) Protons + Neutrons

Question 22. Mass of a ¹²C isotope, in AMU unit is,
(1) 4
(2)12
(3) 1/12
(4) None of them

Answer: (2) 12

Question 23. The ground state electron configuration of potassium (Z = 19) is
(1) 2, 8, 8, 1
(2) 2, 8, 9,0
(3) 2, 9, 8, 0
(4) 2,7, 8, 2

Answer: (1) 2, 8, 8, 1

Question 24: Atoms of which element have no neutron?
(1) Oxygen
(2) Hydrogen
(3) Carbon
(4) Nitrogen

Answer: (2) Hydrogen

Question 25. Which force binds the nucleons?
(1) Gravitational force
(2) Electrostatic force
(e) Nuclear force
(4) None of these

Answer: (3) Nuclear force

Question 26. Which scientist first enunciated the atomic concept of matter?
(1) Newton
(2) Einstein
(3) Dalton
(4) None of these

Answer: (3) Dalton

Question 27. The atomic number is
(1) Mass of an atom x
(2) Total number of protons and neutrons
(3) Number of protons
(4) Number of neutrons

Answer: (3) Number of protons

Question 28. The maximum possible number of electrons in the outermost shell of an atom is
(1) 16
(2) 18
(3) 8
(4) 10

Answer: (3) 8

29. The magnitude of the negative charge an electron carries is
(1) 1.602 x 10^–2 coulombs
(2) 0.602 x 10 ^–9 coulombs
(3) 1.602 x 10^–19 coulombs
(4) 1.602 x 10^–25 coulombs

Answer: (3) 1.602 x 10^–19 coulombs

Question 30. If two isotopes of a certain element are known, it follows: that the atoms of the element
(1) Differ chemically frorn each other
(2) Have different numbers of electrons surrounding their nucle.
(3) Have different numbers of neutrons in their nuclei.
(4) Have the same mass number.

Answer: (3) Have different numbers of neutrons in their nuclei.

Question 31. Which of the following are examples of isotopes
(1) ¹⁴C and , ¹⁴N
(2) ⁴⁰K and, ⁴⁰Ca
(3) ₈ ¹⁶O and ₈ ¹⁸O
(4) None of these

Answer: (3) ₈ ¹⁶O and, ₈ ¹⁸O

Question 32. Sodium atom forms a cation by losing one electron. The cation will be 
(1) S⁺
(2) Na⁺
(3) Kt⁺
(4) None of these

Answer: (2) Na⁺

Question 33. A deuteron contains
(1) A neutron and position
(2) A neutron and a proton
(3) A neutron and two protons
(4) A proton and two neutrons

Answer: (2) A neutron and a proton

Question 34. The nucleus of an atom contains
(1) Electrons
(2) Protons alone
(3) Neutrons alone
(4) Protons and neutrons

Answer: (4) Protons and neutrons

Question 35. The neutron was discovered by
(1) J .J. Thomson
(2) G. T. Seaborg
(3) E. Rutherford
(4) James Chadwick

Answer: (4) James Chadwick

Question 36. The number of electrons in the nucleus of ₆C¹² is
(1) 6
(2) 12
(3) 0
(4) 3

Answer: (3) 0

Question 37. Positron is
(1) _{_1} ⁰e
(2) ₊₁⁰e
(3)  ₁¹H
(4)  None of these

Answer: (2)  ₊₁⁰e

Question 38. The average distance of an electron in an atom from its nucleus is of the order of 
(1) 10⁶m
(2) 10^–6m
(3) 10^–10m
(4) 10^–15m

Answer: (3) 10^–10 m

Question 39. A neutral atom (atomic no. > 1) contains
(1) Proton only
(2) Neutron + Proton
(3) Neutron + Electron
(4) Neutron + Proton + Electron

Answer: (4) Neutron + Proton + Electron

Question 40. The radius of an atom is of the order of
(1) 10^–10cm
(2) 10^–13cm
(3) 10^–15cm
(4) 10^–8cm

Answer: (4) 10^–8 cm

Question 41. Chlorine atom differs from chlorine ion in the number of which of the following ?
(1) Protons
(2) Neutrons
(3) Electrons y
(4) Both Protons and Neutrons

Answer: (3) Electrons

Question 42. Neutrons are present inthe nuclei of all elements except
(1) Hydrogen
(2) Oxygen
(3) Deuterium
(4) Chlorine

Answer: (1) Hydrogen

Question 43. When electrons revolve in stationary orbits 
(1) There is no change in energy level
(2) They become stationary
(3) They are gaining kinetic energy
(4) There is increase in energy

Answer: (1) There is no change in energy level

Question 44. Which of the following isoelectronic species has less electrons than protons?
(1) O^2-
(2) F^–
(3) Na⁺
(4) Mg²⁺

Answer: (1) O^2-

Question 45. As we move away from the nucleus, the energy of an orbit
(1) Decreases
(2) Increases
(3) Remains unchanged
(4) None of these

Answer: (2) Increases

Question 46. By addition of one electron in the outermost shell of a chlorine atom, it produces a
(1) New atom
(2) Anion
(3) Cation
(4) No change

Answer: (2) Anion

Question 47. Nucleons are
(1) Only protons
(2) Only neutrons
(3) Protons and neutrons
(4) Protons, electrons and neutrons

Answer: (3) Protons and neutrons

Question 48. Rutherford’s a-particle scattering experiment led to the discovery of
(1) Electrons
(2) Protons
(3) Neutrons
(4) Atomic nucleus

Answer: (4) Atomic nucleus

Question 49. The electronic configuration of a sodium atom is
(1) 2, 8, 3
(2) 2, 8, 8
(3) 2, 8, 1
(4) 2,5, 3

Answer: (3) 2, 8, 1

Question 50. The valency of the element having electronic configuration 2, 8, 8, 1 is
(1) 1
(2) 2
(3) 3a
(4) 7

Answer: (1) 1

 

Concept Of Mole MCQs

Question 1. 1 mole is the number of atoms in exactly
(1) 1g of  ¹²C
(2) 12 g of ¹²C
(3) 1/12 g of ¹²C
(4) None of these

Answer: (2) 12 g of ¹²C

Question 2. The mass of a C^-12 atom is
(1) 12g
(2) 1/12 g
(3) 12/ N_A g
(4) 12 × N_A g 

Answer: (3)  12/ N_A g

Question 3. The number of moles (n), the number of particles (N) and the Avogadro number (N_A) are related as
(1) n =N_A/N
(2) N/N_A=N
(3) n = N/N_A
(4) n = N.N_A

Answer: (3) n = N/N_A

Question 4. 16 g of oxygen is the mass of oxygen of
(1) One oxygen atom
(2) One oxygen molecule
(3) 1-mole oxygen molecule
(4) One-mole oxygen atom

Answer: (4) One-mole oxygen atom

Question 5. 6.4 g of oxygen is equivalent to
(1) 0.4 mol of oxygen atoms
(2) 0.4 mol of oxygen molecules.
(3) 0.2 mol of oxygen atoms
(4) None of these

Answer. (1) 0.4 mol of oxygen atoms

Question 6. 0.10 mol of carbon is equivalent to
(1) 1.2 g of carbon
(2) 1/12 g of carbon
(3) 12.0 g of carbon
(4) 0.1 g of carbon

Answer:(1) 1.2 g of carbon

Question 7. A sample is known to contain 2 x 6.022 x 10²³. hydrogen atoms. How many mol hydrogen atoms does it contain?
(1)  1 mol
(2) 1/2 mol
(3) 2 mol
(4) N_A mol

Answer: (3) 2 mol

Question 8. Formula mass of water (H₂O) is
(1) 33
(2) 17
(3) 10
(4) 18

Answer: (4) 18

Question 9. Consider two gases A and B or ideal gas with M_A > M_B. The molar volumes (Vm) at given pressure and temperature are like
(1) V_m(A)= V_m(B)
(2) V_m(A)> V_m(B)
(3)V_m(A) <V_m(B)
(4) No relation

Answer: (1) V_m(A)= V_m(B)

Question 10.A sample contains m g of a compound X (mx = molar mass). The sample contains n mol of X. Then n, m and M are related as
(1) M=m.n
(2) M= n/n
(3) M= n/m
(4) n=m.M

Answer: (2) M = m/n

Question 11. ‘Mole’ means
(1) A molecule
(2) Number of molecules
(3) Number of atoms
(4) Avogadro’s number of any particle

Answer: (4) Avogadro’s number of any particle

Question 12. 0.012 kg of C^-12isotope contains how many C^-12atoms ?
(1) 12
(2) 6.022 x10²³
(3) 1.66 x10^-24 g
(4) 12 g atom .

Answer: (2) 6.022 x10²³

Question 13. Avogadro’s number is used in
(1) Chemistry only
(2) Physics only
(3) Biology only
(4) Chemistry, physics and biology

Answer: (4) Chemistry, physics and biology

Question 14. Unit of relative atomic mass is
(1) Gram
(2) Kilogram
(3) a.m.u.
(4) No unit

Answer: (4) No unit

Question 15. Which scientist first gave the concept of molecule?
(1) Dalton
(2) Avogadro
(3) Berzilius
(4) Boyle

Answer: (2) Avogadro

Question 16. What is the volume of 1 gram-molecule of a gas or vapour at NTP?
(1) 22.4 ml
(2) 22.4 lit
(3) 1000 ml
(4) 2.24 lit

Answer: (2) 22.4 lit

Question 17. In the reaction, N₂+3H₂=2NH₃ the ratio of volumes of nitrogen, hydrogen, and ammonia is 1 : 3: 2. These figures illustrate the law of
(1) Constant proportion
(2) Multiple proportion
(3) Reciprocal proportion
(4) Gay Lussac’s law of gaseous volumes

Answer: (4) Gay Lussac’s law of gaseous volumes

Question 18. At NTP, 5.6 lit of a gas weighs 8 grams. The vapour density of the gas is 
(1) 32
(2) 40
(3) 16
(4)  8

Answer: (3) 16

Question 19. Which of the following contains the least number of molecules?
(1) 19 H₂
(2) 2g N₂
(3) 4g O₂
(4) 11g CO₂

Answer: (2) 2g N₂

Question 20. Which of ‘the following volumes of the gas at NTP contains the largest number of molecules?
(1) 200 ml H₂
(2) 100 ml O₂
(3) 150 ml N₂
(4) 22.5 ml NH₃

Answer: (1) 200 ml H₂,

Question 21. Which one of the following statements is not applicable to 1 mole of carbon dioxide?
(1) 22 g CO₂
(2) 22.4 lit of the gas
(3) 1 gram atom of carbon and 2 gram atoms of oxygen
(4) 6.023 x 10²³ molecules of carbon dioxide

Answer: (1) 22 g CO₂

Question 22. A mole of any gas 
(1) Always occupies one liter
(2) Always occupies 22.4 lit at NTP
(3) Can occupy any volume at NTP
(4) Always occupies 11.2 lit at NTP

Answer: (2) Always occupies 22.4 lit at NTP

Question 23. The latest standard of atomic weight is 
(1) Hydrogen = 1
(2) Oxygen = 16
(3) Carbon = 12
(4) Nitrogen = 14

Answer: (3) Carbon = 12

Question 24. The approximate number of molecules in 4.25 g of ammonia is 
(1) 1.0 x 10²³
(2) 1.5 x 10²³
(3) 2.0 x 10²³
(4) 3.5 x 10²³

Answer: (2) 1.5 x 10²³

Question 25. Atomic weight of chlorine is 35.5. It has two isotopes of atomic weights 35 and 37. What is the percentage of the heavier isotope in the sample?
(1)  5
(2) 25
(3) 20
(4) 15

Answer: (2) 25

Question 26 Number of molecules in one litre of water is close to 
(1)\(\frac{6.023}{23.4} \times 10^{23}\)
(2) 18 x 6.023 x 10²³
(3) \(\frac{18}{22.4} \times 10^{23}\)
(4) 55.5 x 6.023 x 10²³

Answer: (4) 55.5 x 6.023 x 10²³

Question 27. Volume at NTP of 0.22 g of CO₂ is the same as that of 
(1) 0.01 g of H₂
(2) 0.085 g of NH₃
(3) 320 mg of gaseous SO₂
(4) All of the above

Answer: (4) All of the above

Question 28. Avogadro’s number of helium atoms weighs 
(1) 1 g
(2) 4 g
(3) 8 g
(4) 4 x 6.025 x10²³ g

Answer: (2) 4 g

Question 29. The molecular mass of CO₂ is 44 a.m.u. Biotec? s number is 6.023 x 10²³, therefore, the mass of one molecule of CO₂ , is
(1) 7.31 x 10^-23
(2) 3.65 x 10^-23
(3) 1.01 x 10^-23
(4) 2.01 x 10^-23

Answer: (1) 7.31 x 10^-23

Question 30. 4.0 grams of caustic soda contain 
(1) 6.023 x 10²³ atoms of hydrogen
(2) 4 g atoms of sodium
(3) 6.023 x 10²²atoms of sodium
(4) 4 moles of caustic soda

Answer: (3) 6.023 x 10²² atoms of sodium:

Question 31. Which of the following weighs the least?
(1) 24 g of magnesium
(2) 0.9 moles of nitric oxide
(3) 22.4 lit of N₂
(4) 6.023 x 10²⁴ molecules of oxygen

Answer: (1) 24 g of magnesium

Question 32. One mole of CO₂ contains
(1) 6.023 x 10²³ atoms of carbon
(2) 6.023 x 10²³ atoms of oxygen
(3) 18.1 x 10²³ molecules of carbon dioxide
(4) 3 gram atoms of carbon dioxide

Answer: (1) 6.023 x 10²³  atoms of carbon

Question 33. One a.m.u. is
(1) 1.00748 g
(2) 0.000549 g
(3) 1.66 x.10^-24 g
(4) 6.023 x 10^-23 g

Answer:  (3) 1.66 x 10^-24g

Question 34. The vapour density of a gas is 11.2. The volume occupied by 11.2 g of the gas at NTP is
(1) 1 L
(2) 11.2 L
(3) 22.4 L
(4) 10 L

Answer: (2) 11.2 L

Question 35. The vapour density of pure ozone would be 
(1) 16
(2) 24
(3) 32
(4) 48

Answer: (2) 24

Question 36. At STP 5.6 lit of a gas weights 60 g. The vapour density of the gas is.
(1) 30
(2) 60
(3) 120
(4) 240

Answer: (3) 120

Question 37. The largest number of molecules is in 
(1) 34 g water
(2) 54 g of CO₂
(3) 46 g of CH₃OH
(4) 54 g of N₂ O₅

Answer : (1) 34 g water

Question 38. The number of oxygen atoms in 4.4 g of CO, is approximately 
(1) 1.2 x 10²³
(2) 6 x 10²³
(3) 6 x10²²
(4) 12 x 10²³

Answer:  (1) 1.2 x 10

Question 39. The number of molecules in 16 g of methane (CH,) is 
(1)  3.0 x 10²³
(2)  6.023 x 10²³
(3) \(\frac{16}{6.023} \times 10^{23}\)
(4) \(\frac{16}{3} \times 10^{23}\)

Answer. (2) 6.023 x 10²³

Question 40. If 0.56 g of a gas occupies 280 ml at NTP, then its molecular mass is 
(1)  4.8
(2)  44.8
(3)  2
(4) 22.4

Answer: (2) 44.8

 

Solution MCQs

Multiple Choice Type :

Question 1. The ratio of the components of a solution is
(1) Fixed
(2) May vary
(3) May vary to any extent
(4) May vary within a limit

Answer: (4) May vary within a limit

Question 2. Aerated cold drinks contain CO₂, sugar, and water. Her solution is of
(1)  Sugar
(2)  CO₂
(3)  Water
(4)  Sugar and CO₂

Answer: (4) Sugar and CO₂ etc

Question 3. Which one is the true solution?
(1) Solution of common salt
(2) Solution of chalk
(3) Milk
(4) Butter

Answer: (1) Solution of common salt

Question 4. The particle size of a colloid is
(1) 10^-8cm
(2) 10^-4 cm
(3) 10^-3cm
(4) 10^-5 cm−10^-7

Answer: (4) 10^-5 cm−10^-7

Question 5. Which one of the following will not diffuse?
a) Suspension
(2) True solution
(3) Colloids
(4) None

Answer: (1) Suspension

Question 6. When liquid is dispersed in a solid, the production is called
(1) Gel
(2) Sol
(3) Emulsion
(4) Foam

Answer: (1) Gel

Question 7. Which of the following in an aqueous solution can enter into the intermolecular space of water?
(1) Urea
(2) Protein
(3) DNA
(4) Starch

Answer: (1) Urea

Question 8. Solubility of which one of the following increases with an increase in temperature 7
(1) O₂
(2) NH₃
(3) KNO₃
(4) SO₂

Answer: (3) KNO₃

Question 9. Which one of the following solutions is unstable?
(1) Saturated
(2) Unsaturated
(3) Supersaturated
(4) Colloidal

Answer: (3) Supersaturated

Question 10. Which one of the following solvents is used to remove nail polish?
(1) Ethyl  alcohol
(2) Methyl alcohol
(3) Acetone
(4) Turpentine oil

Answer: (3) Acetone

Question 11. Solution is a
(1) Mixture
(2) Element
(3) Compound
(4) None of these

Answer: (1) Mixture

Question 12. The solvent of sulphur is
(1) Water
(2) Ethyl alcohol
(3) Carbon disulphide
(4) Benzene

Answer: (3) Carbon disulphide

Question 13. If a saturated solution is heated
(1) Solution becomes unsaturated
(2) Solution becomes super saturated
(3) Solution remains saturated
(4) All of the above

Answer: (2) Solution becomes super saturated

Question 14. If more solvent is added to a saturated solution 
(1) Solution becomes super saturated
(2) Solution becomes unsaturated
(3) Solution remains saturated
(4) All of the above

Answer: (2) Solution becomes unsaturated

Question 15. The solubility of which substance decreases with an increase in temperature?
(1) KNO₃
(2) CaSO₄
(3) NaCl
(4) None of these

Answer: (2) CaSO₄

Question 16. When temperature rises, the solubility of gas in liquid 
(1) Decreases
(2) Increases
(3) Unaltered
(4) None of these

Answer: (1) Decreases

Question 17. If the size of the particles is between 10^-5 cm to 10^-7 cm then the solution will be 
(1) True solution
(2) Suspension
(3) Colloid
(4) None of these

Answer: (3) Colloid

Question 18. The number of water molecules present in washing soda is 
(1)  5
(2)  6
(3) 10
(4)  7

Answer: (3) 10

Question 19. A deliquescent substance is
(1) Magnesium chloride
(2) Washing soda
(3) Glauber’s salt
(4) Blue vitriol

Answer: (1) Magnesium chloride

Question 20. Fog is
(1) A solution of liquid in gas
(2) A solution of gas in gas
(3) A solution of solid in gas
(4) A solution of liquid in liquid

Answer: (1) A solution of liquid in gas

Question 21. Smoke is
(1) A solution of gas in gas
(4) A solution of carbon in gas
(3) A solution of liquid in liquid
(4) A solution of solid in solid

Answer: (4) A solution of carbon in gas

Question 22. Solubility is almost unchanged with rise in temperature in case of 
(1) NaCl
(2) CaSO₄
(3) NaSO₄  , 10 H2O
(4) KNO₃

Answer: (1) NaCl

Question 23. Phosphorus pentoxide is a
(1) Efflorescent substance
(2) Deliquescent Substance
(3) Drying agent
(4) None of these

Answer: (3) Drying agent

Question 24. Is soluble in chloroform.
(1) Sugar
(2) Common salt
(3) Oil
(4) Blue vitriol

Answer: (3) Oil

Question 25. lodine is soluble in
(1) Water
(2) Alcohol
(3) Acetone
(4) None of these

Answer: (2) Alcohol

Question 26. The unit of concentration of the solution is 
(1) g/L
(2) g/m²
(3) g/m
(4) g/cm

Answer: (1) g/L

Question 27. If an excess amount of solute is dissolved in a saturated solution then the solution is Called
(1) Unsaturated solution
(2) Supersaturated solution
(3) Colloid
(4) Emulsion

Answer: (2) Supersaturated solution

Question 28. A solution is 
(1) Solvent dissolved in solute
(2) A heterogeneous mixture
(3) A homogeneous mixture
(4) Only a liquid in liquid

Answer: (3) A homogeneous mixture

Question 29. Depending on “which phase dissolved in which phase”, how many types of solutions do we consider?
(1) 1
(2) 3
(3) 6
(4) 9
Answer: (3) 6

Question 30. A true solution has the feature
(1) Particle size less than 1 mm
(2) Separation by filtration
(3) Solute particles are large groups of particles
(4) Separation by a semipermeable membrane

Answer: (1) Particle size less than 1 mm

Question 31. A colloidal solution is associated with the feature
(1) Solute particles are large groups of insoluble particles
(2) Particle size is 1 to 100 nm
(3) Separation by filtration
(4) None of these

Answer: (2) Particle size is 1 to 100 nm

Question 32. A suspension is associated with the feature
(1) Solutes are atoms or ions
(2) Particle size is 1 to 100 nm
(3) Particle size is less than 100 nm
(4) Separation by filtration

Answer: (4) Separation by filtration

Question 33. Mist or fog are examples of a colloid where A is dispersed in B. A and B are
(1) gas-liquid
(2) liquid – gas
(3) liquid-liquid
(4) solid-liquid

Answer: (2) liquid – gas

Question 34. Which of the following is not a colloidal solution?
(1) Icecream
(2) Milk
(3) Smoke
(4) NaCl in water

Answer: (4) NaCl in water

Question 35. Which of the following is not a technical name for colloids?
(1) Foam
(2) Sol
(3) Gel
(4) Olium

Answer: (4) Olium

Question 36. An alloy is a colloid having dispersed and medium as
(1) Liquid in solid
(2) Solid in liquid
(3) Liquid in liquid
(4) Solid in solid

Answer: (4) Solid in solid

Question 37. Soap or detergent is an example of
(1) Emulsifier
(2) Sol
(3) Aerosol
(4) Solid foam

Answer: (1) Emulsifier

 

Water MCQs

Question 1. The mass ratio of hydrogen and oxygen in water is
(1) 2:1
(2) 1:2
(3) 1:8
(4) 8:1

Answer: (3) 1:8

Question 2. Who first recognised that water is a compound of two elements (hydrogen and oxygen) in 1783?
(1) Lavoisier
(2) Cavendish
(3) J. Thomson
(4) Robert Boyle

Answer: (1) Lavoisier

Question 3. What is the fundamental property that makes water so important?
(1) Density
(2) Its crystal structure
(3) Its boiling point
(4) Hydrogen bonds

Answer: (1) Density

Question 4. In pressure cooker, water boils at T°C; T is
(1) 100°C os
(2) > 100°C
(3) < 100°C
(4) None of these

Answer: (2) > 100°C

Question 5. At 3.98°C (nearly 4°C), water has a special property. What is this?
(1) Density is minimum
(2) Volume is maximum
(3) Density is maximum
(4) None of these

Answer: (3) Density is maximum

Question 6. Water can act as
(1) An. acid only
(2) A base only
(3) Both as acid and a base
(4) Neither acid nor base

Answer: (3) Both as acid and a base

Question 7. ppm is a unit sometimes used to express concentration level of pollutants in water. This ppm is equivalent to
(1) g/l
(2) ml/l
(3) Kg/ml
(4) mg/\(\mathrm{dm}^3\)

Answer: (2) ml/l

Question 8. Hard water contains appreciable amount of concentration of which ions ?
(1) \(\mathrm{Cl}^{-}\) and \(\mathrm{NO}^{-}\)
(2) \(\mathrm{Na}^{+}\) and \(\mathrm{K}^{+}\)
(3)\(\mathrm{CO}^{-2}\) and \(\mathrm{Cl}^{-}\)
(4) \(\mathrm{Ca}^{+2}\) \(\mathrm{Fe}^{+2}\) and \(\mathrm{Mg}^{+2}\)

Answer: (4) \(\mathrm{Ca}^{+2}\) \(\mathrm{Fe}^{+2}\) and \(\mathrm{Mg}^{+2}\)

Question 9. Temporary hardness is due to the presence of which compound in water?
(1) NaCl
(2) \(\mathrm{CaSO}_4\)
(3) \(\mathrm{NaNO}_3\)
(4) \(\mathrm{Ca}\left(\mathrm{HCO}_3\right)_2\)

Answer: (4) \(\mathrm{Ca}\left(\mathrm{HCO}_3\right)_2\)

Question 10. Which state of water provides the medium of life?
(1) Solid
(2) Liquid
(3) Vapour
(4) Vapour at 100°C.

Answer: (2) Liquid

Question 11. Which property of water controls environmental temperature?
(1) Specific heat capcity
(2) Latenet heat of vaporisation
(3) Density
(4) Surface tension.

Answer: (1) Specific heat capcity

Question 12. Air obtained from dissolved air in water contains oxygen and nitrogen respectively in the percentage
(1) 21% \(\mathrm{O}_2\), 78%  \(\mathrm{N}_2\)
(2) 17% \(\mathrm{O}_2\), 83%  \(\mathrm{N}_2\)
(Cc) 33%\(\mathrm{O}_2\), 66% \(\mathrm{N}_2\)
(4) 66% \(\mathrm{O}_2\), 33%  \(\mathrm{N}_2\)

Answer: (3) 33% \(\mathrm{O}_2\)  66% \(\mathrm{N}_2\)

Question 13. What are the prescribed limits of pH of potable water?
(1) 4.5.
(2) 6.5-4.5
(3) 1.5-4.5
(4) 8.5-9.5

Answer: (2) 6.5-4.5

Question 14. Which of the following ions is responsible for the hardness of water?
(1) \(\mathrm{Fe}^{+2}\)
(2) \(\mathrm{Na}^{+}\)
(3)\(\mathrm{HCO}_3^{-}\)
(4)\(\mathrm{SO}_4^{2-}\)

Answer: (1)  \(\mathrm{Fe}^{+2}\)

Question 15. The salt which is the cause of the hardness of water is 
(1) \(\mathrm{NH}_4 \mathrm{Cl}\)
(2) \(\mathrm{NaNO}_3\)
(3) \(\mathrm{MgSO}_4\)
(4) \(\mathrm{K}^{2}{SO}_4\)

Answer: (3) \(\mathrm{MgSO}_4\)

Question 16. Soap is a salt of
(1) Acetic acid
(2) Palmitic acid
(3) Formic acid
(4) Nitric acid

Answer: (2) Palmitic acid

Question 17. Which of the following metals does not react with cold and hot water?
(1) Fe
(2) K
(©) Ni
(4) Ag

Answer: (4) Ag

Question 18. Which of the following is soft water?
(1) Rainwater
(2) River water
(3) Tubewell
(4) Seawater

Answer: (1) Rainwater

Question 19. Which of the following metals reacts easily with water at ordinary temperature?
(1) Ca
(2) Zn
(3) Cu
(4) Ag

Answer: (1) Ca

Question 20. Tubewell water becomes brown due to
(1)\(\mathrm{Ca}\left(\mathrm{HCO}_3\right)_2\)
(2) \(\mathrm{Fe}\left(\mathrm{HCO}_3\right)_2\)
(3) \(\mathrm{MgSO}_4\)
(4) \(\mathrm{MgCl}_2\)

Answer: (2) \(\mathrm{Fe}\left(\mathrm{HCO}_3\right)_2\)

Question 21. D₂O reacts with CaC₂ to form
(1) \(C_2 D_2\)
(2)\({Ca} D_2\)
(3)\(\mathrm{Ca}_2 \mathrm{D}_2 \mathrm{O}\)
(4)\(\mathrm{CD}_2\)

Answer: (1) \(C_2 D_2\)

Question 22. Permutit is regenerated by passing
(1) 10% NaOH solution
(2) 10% \(\mathrm{NH}_4 \mathrm{Cl}\) solution
(3) 10% NaCl solution
(4) None of these

Answer: (3) 10% NaCl solution

Question 23. If 1 lit. water contains 0.001 mol \(\mathrm{MgSO}_4\)what will be the hardness of water ?
(1) 100 ppm
(2) 200 ppm
(3) 500 ppm
(4) 150 ppm

Answer: (3) 500 ppm

Question 24. Water has high boiling point because
(1) Specific heat of water is high
(2) Heat of dissociation is high
(3) Presence of hydrogen bonding
(4) Molecule weight is low

Answer: (3) Presence of hydrogen bonding

Question 25. Anion exhange resin is regenerated by passing
(1) Dilute NaCl solution
(2) Dilute H₂SO4 solution
(3) Dilute HNO3 solution
(4) Dilute NaOH solution

Answer: (4) Dilute NaOH solution

Question 26. When hard water is passed through zeolite, the Na* (present in zeolite) is exchanged by
(1) \(\mathrm{OH}^{-}\)
(2) \(\mathrm{Ca}^{+2}\)
(3) \(\mathrm{SO}^{-2}\)
(4)\(\mathrm{H}^{+}\)

Answer: (2) \(\mathrm{Ca}^{+2}\)

Question 27. Water is oxidised to oxygen by
(1) \(\mathrm{ClO}_2\)
(2) \(\mathrm{KMnO}_4\)
(3) \(\mathrm{H}_2 {O}_2\)
(4) \(\mathrm{F}_2\)

Answer: (4) \(\mathrm{F}_2\)

Question 28. Sodium promptly reacts with water at ordinary temperature to form sodium hydroxide and what?
(1) Oxygen
(2) Nitrogen
(3) Chlorine
(4) Hydrogen

Answer: (4) Hydrogen 3

 

Separation Of Components Of Mixture MCQs

Question 1. A solution of sugar in water is
(1) A homogeneous mixture
(2) A heterogeneous mixture
(3) Separated by separating funnel
(4) None of these

Answer: (1) A homogeneous mixture

Question 2. Bronze is an example of
(1) Solid in a solid homogeneous mixture
(2) Solid is a solid heterogeneous mixture
(3) A solid is a liquid homogeneous mixture
(4) Solid in a liquid heterogeneous mixture

Answer: (1) Solid in solid homogeneous mixture

Question 3. Which one is a solid in liquid homogeneous mixture?
(1) Gunpowder
(2) Water in sponge
(3) iodine in alcohol
(4) Oil in water

Answer: (3) iodine in alcohol

Question 4. A mixture of common salt (NaCl) and \(\mathrm{NH}_4 \mathrm{Cl}\) (s) can be separated by
(1) Magnetic separation
(2) Mechanical picking
(3) Sublimation
(4) Filtration

Answer: (3) Sublimation

Question 5. Sedimentation and decantation is a method of separation suitable for
(1) Solid in a solid homogeneous mixture
(2) Liquid in liquid homogeneous mixture
(3) Solid in a liquid heterogeneous mixture
(4) Solid in a solid heterogeneous mixture

Answer: (3) Solid in a liquid heterogeneous mixture

Question 6. Fractional distillation is used for the separation of which type of mixture?
(1) Solid in liquid mixture
(2) Liquid in solid
(3) Liquid-liquid immiscible
(4) Liquid-liquid miscible

Answer: (4) Liquid-liquid miscible

Question 7. The use of a separatory funnel
(1) Depends on the volume ratio of two liquids
(2) Depends on the density difference between two liquids
(3) Depends on difference in boiling points of the liquids
(4) Depends on the color of the liquids

Answer: (2) Depends on the density difference between two liquids

Question 8. The use of fractional distillation depends on
(1) Volume ratio of liquids
(2) Density ratio of liquids
(3) Difference in boiling points of the liquids
(4) Color of the liquids

Answer: (3) Difference in boiling points of the liquids

Question 9. Which one is not a product of fractional distillation of crude petroleum?
(1) Petrol
(2) Diesel
(3) Ethanol
(4) Kerosene

Answer: (3) Ethanol

Question 10. Water boils at 100°C under a pressure of
(1) 760 cm of Hg
(2) 76 cm of Hg
(3) 7.6 mm of Hg
(4) 7.6 cm of Hg

Answer: (2) 76 cm of Hg

Question 11. The method to separate sugar from its aqueous solution ignoring the collection of water is S
(1) Evaporation
(2) Distillation
(3) Sedimentation
(4) Centrifugation

Answer: (1) Evaporation

Question 12. lodine and ethanol are separated from their mixture by
(1) Filtration
(2) Evaporation
(3) Distillation
(4) Fractional distillation

Answer: (3) Distillation

Question 13. A mixture of carbon tetrachloride and water is separated by using
(1) Funnel
(2) Separating funnel
(3) Beaker
(4) Fractionating column

Answer: (2) Separating funnel

Question 14. The boiling point of a liquid
(1) Decreases with increase in pressure
(2) The boiling point does not affect the pressure
(3) Increases with increase in pressure
(4) Does not always increase with the increase in pressure

Answer: (3) Increases with increase in pressure

Question 15. The components of crude oil are separated by
(1) Fractional distillation
(2) Distillation
(3) Separating funnel
(4) None of these

Answer: (1) Fractional distillation

Question 16. Alcohol and water mixture can be separated by
(1) Distillation
(2) Filtration
(3) Fractional distillation
(4) None of the above

Answer: (1) Distillation

Question 17. Carbon disulfide and water mixture can be separated by 
(1) Filtration
(2) Decantation
(3) Separating funnel
(4) None of the above

Answer: (3) Separating funnel

Acids, Bases And Salts MCQs

Question 1. An aqueous solution turns blue litmus solution red. Excess addition of which of the following solutions to the above solution reverses the change?
(1) HCl solution
(2) Vinegar solution
(3) H₂SO₄
(4) Caustic soda solution

Answer: (4) Caustic soda solution

Question 2. Which of the following substances changes the colour of pH paper to greenish-blue?
(1) Common salt
(2) Vinegar
(3) An antacid
(4) Orange juice

Answer: (3) An antacid

Question 3. To protect tooth decay you are advised to brush your teeth regularly, the nature of commonly used paste is
(1) Neutral
(2) Acidic
(3) Basic
(4) Corrosive

Answer: (3) Basic

Question 4. If you soak a pH paper into gastric juice, it will indicate a pH 
(1) More than 7
(2) Less than 7
(3) Equal to 7
(4) Less than 1

Answer: (2) Less than 7

Question 5. Which of the following gases is responsible for acid rain?
(1) N₂
(2) CH₄
(3) S₂
(4) H₂

Answer: (3) SO₂

Question 6. Which element is present in all acids?
(1) Hydrogen
(2) Oxygen
(3) Carbon
(4) Nitrogen

Answer: (1) Hydrogen

Question 7. ZnO is
(1) Acidic
(2) Basic
(3) Amphoteric
(4) Neutral oxide

Answer: (3) Amphoteric

Question 8. The weak acid is
(1) HCI
(2) HNO₃
(3) H₂SO₄
(4) H₂CO₃

Answer: (4) H₂CO₃

Question 9. Aqueous solution of P.O is
(1) HPO₃
(2) H₃PO₄
(3) H₃PO₃
(4) H₃PO₂

Answer: (2) H₃PO₄

Question 10. Methyl orange is
(1) Base
(2) Alkali
(3) Indicator
(4) Oxide

Answer: (3) Indicator

Question 11. Minimum quantity of indicator used in neutralisation reaction is
(1) 5 ml
(2) 5.2 ml
(3) 5.5 ml
(4) 2-3 drops

Answer: (4) 2-3 drops

Question 12. The aqueous solutions of bases turn red litmus to
(1) Blue
(2) Colourless
(3) Violet
(4) Yellow

Answer: (1) Blue

Question 13. NaCl is a salt.
(1) Normal
(2) Acid
(3) Basic
(4) Complex

Answer: (1) Normal

Question 14. A strong acid is
(1) H₂SO₄
(2) H₂CO₃
(3) H₃PO₄
(4) CH₃COOH

Answer: (1) H₂SO₄

Question 15. Caustic soda is a base.
(1) Salt
(2) Weak
(3) Strong
(4) Acid

Answer: (3) Strong

Question 16. Sulphuric acid is a/an
(1) Inorganic acid
(2) Organic acid
(3) Weak acid
(1) Hydracid

Answer: (1) Inorganic acid

Question 17. Disolium hydrogen phosphate is a
(1) Normal salt
(2) Basic salt
(3) Acid salt
(4) Double salt

Answer: (3) Acid salt

Question 18. Which of the following compounds is used to prepare vanishing colour ?
(1) NH₄OH
(2) NaOH
(3) Ca(OH)₂
(4) KOH

Answer: (1) NH₄OH

Question 19. Na₂SO₄ is a
(1) Normal salt
(2) Acid salt
(3) Basic salt
(4) Complex salt

Answer: (1) Normal salt

Question 20. Indicator used for neutralisation reaction of H₂SO₄ and NaOH is
(1) Methyl orange
(2) Phenolphthalein
(3) Litmus
(4) Any indicator

Answer: (4) Any indicator

Question 21. The colour of phenolphthalein in dilute sulphuric acid solution is
(1) Red
(2) Yellow
(3) Blue
(4) Colourless

Answer: (4) Colourless

Question 22. The colour of methyl orange in acidic solution is
(1) Red
(2) Yellow
(3) Blue
(4) Orange

Answer: (1) Red

Question 23. Sulphuric acid contains replaceable hydrogen atom/atoms by a metal.
(1) 1
(2) 2
(3) 3
(4) 4

Answer: (2) 2

Question 24. Ammonia is
(1) An acid
(2) A base
(3) A salt
(4) None of thesg

Answer: (2) A base

Question 25. The acidity of CaO is
(1) 1
(2) 2
(3) 3
(4) 4

Answer: (2) 2

Question 26.The basicity of hydrochloric acid is 
(1) 1
(2) 2
(3) 3
(4) 4

Answer: (1) 1

Question 27. Phosphoric acid is a
(1) Monobasic
(2) Dibasic
(3) Tribasic acid
(4) None of these

Answer: (3) Tribasic acid

Question 28. Which one is not an Arrhenius acid?
(1) HCI
(2) HF
(3) HNO₃
(4) C₂H₂

Answer: (4) C₂H₂

Question 29. An acid is a compound
(1) Having hydrogen atom
(2) Having lone pair of electron
(3) That can donate proton
(4) That can accept proton

Answer: (1) Having hydrogen atom

Question 30. A base is that
(1) Has oxygen atom
(2) Can accept proton
(3) Can donate proton
(4) Is sour in taste
Answer: (1) Has oxygen atom

Question 31. Which one is amphoteric?
(1) HCN
(2) NH₃
(3) NaOH
(4) H₂O

Answer: (3) NaOH

Question 32. Which one is a weak acid?
(1) HNO₃
(2) HCI
(3) H₂SO₄
(4) CH₃COOH

Answer: (4) CH₃COOH

Question 33. Baking soda consists of
(1) Na₂CO₃
(2) H₂CO₃
(3) NaHCO₃
(4) CH₃COOH

Answer: (3) NaHCO₃

Question 34. Baking powder is a mixture of NaHCO₃ and
(1) Vinegar
(2) CH₃COOH
(3) Oxalic acid
(4) Tartaric acid

Answer: (4) Tartaric acid

Question 35. Which one is a salt?
(1) HCI
(2) NH₃
(3) NaCl
(4) H₂O

Answer: (3) NaCl

Question 36. Which one is a normal salt?
(1) Na₂SO₄
(2) NaHSO₄
(3) NaHCO₃
(4) Pb(OH)CI

Answer: (1) Na₂SO₄

Question 37. Which one is an acid salt?
(1) NaHSO₄
(2) NaCl
(3) NaSO₄
(4) Cu(OH)NO

Answer: (1) NaHSO₄

Question 38. Which one is a basic salt?
(1) Na₂SO₄
(2) Na₂HPO₄
(3) NaCl
(4) Pb(OH)CI

Answer: (4) Pb(OH)Cl

Question 39. Which one is a double salt?
(1) Ca (OCI)CI (Bleaching powder)
(2) NaKCO₃
(3) [Cu (NH₃)₄]SO₄
(4) FeSO₄.(NH₄)₂SO₄.6H₂O (Mohr’s salt)

Answer: (4) FeSO₄.(NH₄)₂SO₄.6H₂O (Mohrs salt)

40. pH is defined as
(1)  (H₃O⁺)
(2)  log (H₃O⁺)
(3) −log (H₃O⁺)
(4) −(H₃O⁺)

Answer: (3) −log (H₃O⁺)

Question 41. In neutral water at 25°C, [H⁺] in mol/ is
(1) 10⁷
(2) 10.7
(3) 10^-7
(4) 1.0

Ans, (3) 10^-7

Question 42. An acid-base indicator is an organic dye which is chemically
(1) A weak acid
(2) A weak base
(3) Either a weak acid or a weak base
(4) A strong acid or a base

Answer: (3) Either a weak acid or a weak base

Question 43. Acid turns a blue litmus paper to
(1) Red
(2) Deep violet
(3) Green
(4) Colourless

Answer: (1) Red

Question 44.Id and strong base
(2) Weak base-strong acid
(3) Strong acid-strong base
(4) Both strong acid-strong base and weak acid-strong base

Answer: (1) Weak acid and strong base

Question 45. By acid rain, the pH of water body
(1) Is reduced
(2) Is increased
(3) Remains the same
(4) None

Answer: (1) Is reduced