PHYSICAL CHEMISTRY MCQs

1. Which statement is true?

(A) All elements are heterogeneous

(B) A mixture is forever heterogeneous

(C) Air is a homogenous mixture

(D) Compounds made up of a number of elements are heterogeneous

2. The study of numerous laws and principles governing chemical and physical changes is called _____ .

(A) Analytical Chemistry

(B) Physical Chemistry

(C) Organic Chemistry

(D) Inorganic Chemistry

3. Which is not an element?

(A) Silica

(B) Diamond

(C) Graphite

(D) Plastic sulfur

4. Which is not a mixture?

(A) Iodized table salt

(B) Gasoline

(C) Distilled water

(D) Sugar dissolved in water

5. Which statement is false?

(A) Milk is a homogenous mixture

(B) Homogenous mixtures are called solutions

(C) An element of a substance contains only one kind of atoms

(D) A compound can be decomposed into its constituents

6. A mixture of sand and ammonium chloride can be separated by

(A) Sublimation

(B) Chromatography

(C) Fractional crystallization

(D) Gravity separation

7. Calcium sulfate containing sodium sulfate as impurity is separated by which of the following?

(A) Fractional crystallization

(B) Chromatography

(C) Sublimation

(D) Filtration and crystallization

8. Which is not a compound?

(A) Carborundum

(B) Marble

(C) Ozone

(D) Quick lime

9. Which is false with respect to SI units?

(A) Amount of substance in mol/L

(B) Density in kg/m

(C) Pressure in Pascal

(D) Force in Newton

10. Which process results in a chemical change?

(A) Heating of a platinum rod

(B) Dissolving of common salt in water

(C) Sublimation of ammonium chloride

(D) Heating of iron rod

11. What is the relationship between picometer (pm) and nanometer (nm)?

(A) 1 pm = 10 nm

(B) 1 nm = 1000 pm

(C) 1 pm = 100 nm

(D) 1 nm = 10 pm

12. The atmospheric pressure of one torr is equal to which of the following?

(A) 1 mm of Hg

(B) 1 cm of Hg

(C) 1 m of Hg

(D) 1 atm pressure

13. Which is true?

(A) 1L = 1m³

(B) 1dm³ = 10³ cm³

(C) 1dm³ = 10 L

(D) 1L = 10 dm³

14. According to ______, the percentage of hydrogen in water and hydrogen peroxide is 11.1 and 5.9% respectively.

(A) Avogadro’s law

(B) Law of conservation of mass

(C) Law of definite proportion

(D) Law of multiple proportion

15. The balancing of a chemical equation is based on which law?

(A) Law of conservation of mass

(B) Law of definite proportion

(C) Avogadro’s law

(D) Law of multiple proportion

16. Which liquid mixture cannot be separated by simple distillation?

(A) Ethanol and methanol

(B) Benzene and toluene

(C) Acetone and methanol

(D) Water and ethanol

17. Which is the most abundant element in Earth’s crust?

(A) Aluminum

(B) Nitrogen

(C) Iron

(D) Oxygen

18. The isotopes of chlorine with mass number 35 and 37 exist in which ratio?

(A) 3:1

(B) 3:2

(C) 1:3

(D) 2:2

19. What is the value of Avogadro’s number?

(A) 6.6230 × 10⁻³⁴

(B) 5.024 × 10²²

(C) 6.02200 × 10²¹

(D) 6.02252 × 10²³

20. What is the mass of one mole of an electron?

(A) 1.008 mg

(B) 0.55 mg

(C) 0.184 mg

(D) 1.637 mg

21. Which has maximum mass?

(A) 0.1 gram atom of nitrogen

(B) 0.1 mole of ammonia

(C) 6.022 × 10 molecules of He gas

(D) 12 cm of carbon dioxide

22. What is the volume occupied by 1.4 g of N₂ at STP?

(A) 2.24 dm³

(B) 0.112 dm³

(C) 1.12 dm³

(D) 22.4 dm³

23. Total number of atoms present in 64 g of SO₂ is

(A) 6.02 × 10²²

(B) 64 × 6.02 × 10²²

(C) 64 × 6.02 × 10²³

(D) 6.02 × 10²³

24. What is the approximate mass of one a.m.u?

(A) 1.66 × 10²¹ g

(B) 2.0 g

(C) 1.66 × 10⁻²⁴ g

(D) 1.0 g

25. Which substance is helpful and used as CO₂ absorber in combustion analysis?

(A) Dilute NaOH

(B) 50% KOH

(C) Lime water

(D) Mg(OH)₂

26. The weights of two elements which combine with one another are in the ratio of their ____ .

(A) Molecular mass

(B) Equivalent mass

(C) Atomic mass

(D) Gram mole

27. The equivalent mass of KMnO₄ in acidic medium (K = 39, Mn = 55, O = 16)

(A) 158

(B) 15.8

(C) 31.6

(D) 3.16

28. Which is the atomic mass of an element?

(A) The actual mass of one atom of the element

(B) The relative mass of an atom of the element

(C) Theoretical mass of an atom of the element

(D) The average relative mass of different atoms of the element

29. Which represents 1 gram molecule of a substance?

(A) 6.02 × 10²⁴ molecules of ammonia

(B) 120 gram of iodine

(C) 32 g of O₂

(D) 40 gram of CaO

30. What is the number of moles of SO₂ in 6.4 gram?

(A) 0.01

(B) 0.2

(C) 0.1

(D) 0.02

31. What is the empirical formula of oxalic acid?

(A) CHO₂

(B) CH₂O

(C) CHO

(D) CH₂O₂

32. Which one of the following contains 44 maximum numbers of molecules?

(A) 16 gram sulfur dioxide

(B) 16 gram methane

(C) 16 gram oxygen molecule

(D) 16 gram water

33. What is the mass of the electron?

(A) 9.1195 × 10⁻⁴¹ g

(B) 9.1095 × 10⁻³¹ mg

(C) 9.1095 × 10⁻³¹ kg

(D) 9.1095 × 10⁻²⁷ kg

34. Which pairs of compounds illustrate law of multiple proportions?

(A) CsOH, KOH

(B) Benzene and ethane

(C) KI and KCl

(D) D₂O and H₂O

35. Which property is forever in whole numbers?

(A) Atomic mass

(B) Atomic radius

(C) Atomic volume

(D) Atomic number

36. Isotopes differ in which of the following?

(A) Arrangement of electrons in orbitals

(B) Properties depending on mass

(C) Arrangement of protons in the nucleus

(D) Chemical properties

37. The technique helpful and used to separate insoluble particles from liquid is:

(A) Sublimation

(B) Crystallization

(C) Filtration

(D) Solvent extraction

38. Actual yield of a chemical reaction is forever less than the theoretical yield because of

(A) Reversible reactions

(B) Side reactions

(C) By-product formation

(D) All of A, B, and C

39. The process controlled by distribution law is

(A) Solvent extraction

(B) Sublimation

(C) Filtration

(D) Crystallization

40. Number of peaks in mass spectrum shows

(A) Number of protons

(B) Mass number

(C) Relative abundance

(D) Number of isotopes

41. Which substance is helpful and used as decolorizing agent?

(A) Animal charcoal

(B) Sulfuric acid

(C) Asbestos

(D) Silica gel

42. Which is not helpful and used as drying agent in desiccators?

(A) Silica gel

(B) CaCl₂

(C) P₂O₅

(D) NaCl solution

43. The separation of miscible liquids by heating due to difference in boiling points is called __ .

(A) Vaporization

(B) Sublimation

(C) Condensation

(D) Distillation

44. Which is not locating reagent?

(A) Rubeanic acid

(B) H₂S

(C) CS₂

(D) Ninhydrin

45. Which is the safe and most reliable method of drying crystals?

(A) Furnace

(B) Vacuum oven

(C) Oven

(D) Desiccator

46. Which is insoluble in water but soluble in KI solution?

(A) Benzoic acid

(B) Aspirin

(C) Iodine

(D) Ether

47. Mixture of NaCl and ammonium chloride is separated by which of the following?

(A) Filtration

(B) Crystallization

(C) Solvent extraction

(D) Sublimation

48. Equal volumes of different gases at any definite temperature and pressure have _____ molecules.

(A) Equal atoms

(B) Equal molecules

(C) Equal masses

(D) Equal densities

49. Which is the most suitable locating reagent for amino acids on paper chromatography?

(A) H₂S

(B) Rubeanic acid

(C) Ninhydrin

(D) Sulfuric acid

50. The solid _____ is left over the filter paper.

(A) Filtrate

(B) Aliquot

(C) Residue

(D) Crystals

51. Which is not macromolecule?

(A) Sucrose

(B) Cellulose

(C) Hemoglobin

(D) Glycogen

52. The ideal standard of atomic mass is

(A) Hydrogen-1.008

(B) Oxygen-16

(C) Chlorine-35.5

(D) Carbon-12

53. Height of a peak in mass spectrum shows ______.

(A) Mass number

(B) Relative abundance

(C) Number of isotopes

(D) Number of protons

54. What is the approximate diameter of the atom?

(A) 2.0 nm

(B) 2.0 mm

(C) 0.2 nm

(D) 2.0 cm

55. Which elements give single peak in mass spectrum?

(A) Hydrogen

(B) Chlorine

(C) Bromine

(D) Iodine

56. Which is the volume occupied by 28 g of N₂ at STP?

(A) 22.414 dm³

(B) 224.14 dm³

(C) 2.2414 dm³

(D) None of A, B, and C

57. Solvent extraction is based on which of the following?

(A) Amount of solvent

(B) Distribution law

(C) Law of mass action

(D) Amount of solute

58. The rate at which solute moves in paper chromatography depends on which of the following?

(A) Retardation factor of the solute

(B) Size of the tank

(C) Temperature of the experiment

(D) Size of the paper

59. Which is a separation technique?

(A) All of A, B, and C

(B) Chromatography

(C) Filtration

(D) Crystallization

60. Which is most convenient way of filtration?

(A) Fluted filter paper

(B) Gooch crucible

(C) Filter Paper

(D) Sintered glass crucible

61. A sample in the ionization chamber of mass spectrometer is ionized by

(A) Nucleus

(B) Protons

(C) Neutrons

(D) Electrons

62. Direct conversion of solids into vapors is called ______ .

(A) Sublimation

(B) Vaporization

(C) Distribution

(D) Evaporation

63. The rate of filtration can be increased by which of the following?

(A) Suction apparatus

(B) Desiccator

(C) Chromatographic tank

(D) None of A, B, and C