ICSE Class 6 Chemistry - Pure Substances and Mixtures - Test 4 (Expert)
1. A teacher shows a sample that has the same kind of particles throughout. What can it be called?
A. Heterogeneous mixture
B. Pure substance
C. Dusty mixture
2. Two students make lemonade. One adds more sugar than the other. This shows that a mixture:
A. Always has fixed composition
B. Cannot contain water
C. Can have variable composition
3. A piece of granite shows different coloured particles. It is most likely a:
A. Heterogeneous mixture
B. Pure element
C. Pure compound only
4. Vinegar looks uniform from top to bottom. It is best described as a:
A. Heterogeneous mixture
B. Homogeneous mixture
C. Pure metal
5. Oil is added to water and two layers are formed. This shows that the mixture is:
A. A pure substance
B. A compound
C. Heterogeneous
6. A mixture contains iron filings and sugar. Which method is best to remove iron filings?
A. Magnetic separation
B. Evaporation only
C. Freezing only
7. After preparing tea, which method can remove tea leaves from the liquid tea?
A. Magnetism
B. Filtration
C. Melting
8. A dirty water sample is left still for some time. The heavier dirt settles at the bottom. This process is:
A. Evaporation
B. Sieving
C. Sedimentation
9. After mud settles in muddy water, the clear water is carefully poured into another vessel. This is called:
A. Decantation
B. Freezing
C. Dissolving
10. Which method can separate small sand particles from larger stones?
A. Condensation
B. Sieving
C. Magnetism only
11. A coloured crystal is dissolved in water and the whole liquid becomes coloured. This shows that the solute:
A. Stays only at the bottom
B. Becomes a stone
C. Spreads throughout the solvent
12. Sugar is added to water again and again until some sugar remains at the bottom. The solution is now:
A. Saturated
B. Pure element
C. Empty solvent
13. A very sweet sugar solution is mixed with more water. The solution becomes:
A. More concentrated
B. More dilute
C. A pure metal
14. Brass is made by mixing copper and zinc. Brass is a:
A. Pure element
B. Pure compound only
C. Mixture
15. Sea water is not a pure substance because it contains:
A. Dissolved salts and other substances
B. Only one kind of particle
C. Only oxygen atoms
16. A sample of pure common salt will have:
A. Different visible parts in every spoon
B. Fixed composition throughout
C. Sand mixed with it always
17. Muddy water is filtered. Which statement is correct?
A. Mud passes completely through the filter paper
B. Water becomes a gas immediately
C. Mud stays on the filter paper
18. Salt solution is heated in an evaporating dish. What is left after the water evaporates?
A. Salt
B. Sand only
C. Oxygen only
19. Which mixture can be separated using filtration?
A. Sugar dissolved in water
B. Sand mixed with water
C. Salt dissolved completely in water
20. Which statement correctly compares a pure substance and a mixture?
A. A pure substance is always made by sieving
B. A mixture always has fixed composition
C. A mixture can often be separated by physical methods