1. Which of the following is not a pure substance?
a) Water
b) Air
c) Diamond
d) Gold
Answer: b) Air
2. The process of converting a solid directly into a gas without passing through the liquid
state is called:
a) Condensation
b) Sublimation
c) Evaporation
d) Melting
Answer: b) Sublimation
3. What is the boiling point of pure water at standard atmospheric pressure?
a) 100°C
b) 0°C
c) 212°F
d) 373 K
Answer: a) 100°C
4. Which method is used to separate components of a mixture with different boiling points?
a) Filtration
b) Chromatography
c) Distillation
d) Sublimation
Answer: c) Distillation
5. Which of the following is a homogeneous mixture?
a) Orange juice with pulp
b) Sand and water
c) Saltwater
d) Oil and vinegar
Answer: c) Saltwater
6. The process of conversion of a gas directly into a solid without passing through the liquid
state is called:
a) Deposition
b) Condensation
c) Sublimation
d) Solidification
Answer: a) Deposition
7. Which of the following methods is used to separate an insoluble solid from a liquid?
a) Distillation
b) Sublimation
c) Filtration
d) Chromatography
Answer: c) Filtration
8. Which of the following statements is true about a solution?
a) It is a heterogeneous mixture.
b) It contains only solute.
c) It has a fixed composition.
d) It cannot be separated by physical methods.
Answer: c) It has a fixed composition.
9. Which of the following is a compound?
a) Air
b) Carbon
c) Saltwater
d) Soil
Answer: c) Saltwater
10. The property of a substance to be hammered into thin sheets is called:
a) Ductility
b) Malleability
c) Solubility
d) Viscosity
Answer: b) Malleability
11. An example of a physical change is:
a) Rusting of iron
b) Burning of wood
c) Cooking an egg
d) Melting of ice
Answer: d) Melting of ice
12. Which of the following is a chemical change?
a) Boiling water
b) Dissolving sugar in water
c) Digesting food
d) Cutting paper
Answer: c) Digesting food
13. Which of the following is a heterogeneous mixture?
a) Vinegar
b) Milk
c) Soda water
d) Air
Answer: b) Milk
14. Which of the following substances has the highest boiling point?
a) Ethanol (alcohol)
b) Water
c) Petrol
d) Kerosene
Answer: b) Water
15. The process of separation of different components of a mixture into their original state is
called:
a) Filtration
b) Evaporation
c) Sublimation
d) Decantation
Answer: b) Evaporation
16. The method used to separate colors in ink is called:
a) Filtration
b) Chromatography
c) Sublimation
d) Decantation
Answer: b) Chromatography
17. Which of the following is not a physical property of matter?
a) Color
b) Density
c) Flammability
d) Solubility
Answer: c) Flammability
18. Which of the following is an example of a pure substance?
a) Sea water
b) Sand
c) Oxygen gas
d) Colored candy
Answer: c) Oxygen gas
19. Which of the following is a mixture?
a) Hydrogen gas
b) Copper wire
c) Brass
d) Sodium chloride (table salt)
Answer: c) Brass
20. Which of the following methods is used to separate components of a mixture based on
their particle size?
a) Distillation
b) Filtration
c) Evaporation
d) Sedimentation
Answer: b) Filtration
21. The process of converting a liquid into a gas is called:
a) Melting
b) Boiling
c) Condensation
d) Freezing
Answer: b) Boiling
22. Which of the following is a pure substance?
a) Air
b) Soil
c) Mercury
d) Vinegar
Answer: c) Mercury
23. The separation technique used to separate a mixture of oil and water is:
a) Filtration
b) Distillation
c) Decantation
d) Chromatography
Answer: c) Decantation
24. The minimum number of phases that can exist in a heterogeneous system is:
a) 1
b) 2
c) 3
d) 4
Answer: b) 2
25. Which of the following substances does not exist in a pure state in nature?
a) Gold
b) Oxygen
c) Salt
d) Air
Answer: d) Air
26. Q: Which of the following mixtures exhibits Tyndall effect?
a) True Solution
b) Colloidal Solution
c) Suspension
d) Both b) and c)
Answer: d) Both b) and c)
27. Q: In a true solution, the solute particles are:
a) Large and visible
b) Medium-sized and dispersed
c) Very small and evenly distributed
d) Not uniformly mixed
Answer: c) Very small and evenly distributed
28. Q: Milk of Magnesia is an example of:
a) True Solution
b) Colloidal Solution
c) Suspension
d) None of the above
Answer: b) Colloidal Solution
29. Q: Which of the following mixtures is stable and does not separate on standing?
a) True Solution
b) Colloidal Solution
c) Suspension
d) None of the above
Answer: a) True Solution
30. Q: The particles in a colloidal solution are larger than those in a true solution but smaller
than those in a suspension. True or False?
a) True
b) False
Answer: b) False
31. Q: Which of the following methods can be used to separate a suspension?
a) Evaporation
b) Filtration
c) Distillation
d) Tyndall effect
Answer: b) Filtration
32. Q: Which of the following is an example of a suspension?
a) Saltwater
b) Lemonade
c) Sand and water
d) Milk
Answer: c) Sand and water
33. Q: Which of the following is a characteristic property of colloidal solutions?
a) They are transparent and do not scatter light.
b) They settle down rapidly on standing.
c) They can pass through ordinary filter paper.
d) They cannot be separated by centrifugation.
Answer: c) They can pass through ordinary filter paper.
34. Q: Which of the following mixtures is the most stable and does not separate even on
prolonged standing?
a) True Solution
b) Colloidal Solution
c) Suspension
d) None of the above
Answer: a) True Solution
35. Q: Gelatin, used in making jellies, is an example of which type of mixture?
a) True Solution
b) Colloidal Solution
c) Suspension
d) None of the above
Answer: b) Colloidal Solution
36. Q: Which of the following is an example of an element?
a) Water (H2O)
b) Carbon dioxide (CO2)
c) Oxygen (O2)
d) Salt (NaCl)
Answer: c) Oxygen (O2)
37. Q: An element is made up of:
a) Two or more types of atoms chemically combined.
b) Two or more elements chemically combined.
c) A single type of atom.
d) A single type of molecule.
Answer: c) A single type of atom.
38. Q: Which of the following is a compound?
a) Nitrogen (N2)
b) Hydrogen (H2)
c) Methane (CH4)
d) Helium (He)
Answer: c) Methane (CH4)
39. Q: Compounds can be broken down into simpler substances by:
a) Chemical methods only
b) Physical methods only
c) Both chemical and physical methods
d) Neither chemical nor physical methods
Answer: a) Chemical methods only
40. Q: Which of the following is true about compounds?
a) They can exist as a single atom.
b) They have a fixed composition.
c) They can be separated into elements by physical methods.
d) They are always gases at room temperature.
Answer: b) They have a fixed composition.
41. Q: An example of a heterogeneous mixture that can be separated into its components is:
a) Air
b) Saltwater
c) Soil
d) Vinegar
Answer: c) Soil
42. Q: The chemical formula H2O represents:
a) An element
b) A compound
c) A mixture
d) A solution
Answer: b) A compound
43. Q: Which of the following statements is correct regarding elements?
a) They can be broken down into simpler substances.
b) They cannot be classified into groups.
c) They are the basic building blocks of compounds.
d) They are always found in liquid state.
Answer: c) They are the basic building blocks of compounds.
44. Q: A compound differs from an element in terms of:
a) The number of atoms it contains.
b) Its physical state at room temperature.
c) The types of atoms it contains.
d) Its color and appearance.
Answer: c) The types of atoms it contains.
45. Q: Which of the following is a mixture?
a) Hydrogen (H2)
b) Sodium (Na)
c) Carbon dioxide (CO2)
d) Air
Answer: d) Air
