ICSE Class 6 Chemistry - Pure Substances and Mixtures - Test 3 (Advanced)
1. Which statement best explains why pure copper is a pure substance?
A. It is shiny
B. It has the same kind of particles throughout
C. It can be bent into wire
2. Why is a mixture of sand and salt not called a compound?
A. It has no mass
B. It is always a liquid
C. Its components are only physically mixed
3. A mixture of sand and salt is stirred with water. Which substance dissolves?
A. Salt
B. Sand
C. Filter paper
4. Muddy water is left undisturbed. The mud settles down. Which method can remove the clear water above it?
A. Melting
B. Decantation
C. Magnetism only
5. What happens during sedimentation?
A. Salt changes into gas
B. Water becomes a metal
C. Heavy insoluble particles settle down
6. Which observation shows that a salt solution is homogeneous?
A. It looks the same throughout
B. Salt grains are seen at the top
C. Sand particles float in it
7. A bowl contains peanuts, raisins, and cornflakes. It is heterogeneous because:
A. It is a pure compound
B. Its parts can be seen separately
C. It contains only one substance
8. When a little salt is dissolved in water, the salt:
A. Becomes sand
B. Remains as large visible stones
C. Spreads evenly in the water
9. In a salt solution, which substance is the solute?
A. Salt
B. Water
C. Beaker
10. In a salt solution, which substance acts as the solvent?
A. Salt
B. Water
C. Glass rod
11. Two glasses have the same amount of water. Glass X has one spoon of sugar, and Glass Y has three spoons. Which is more concentrated?
A. Glass X
B. Both have no solute
C. Glass Y
12. A solution with very little salt in a large amount of water is called:
A. Dilute solution
B. Pure element
C. Dry mixture
13. In filtration, what is usually used to separate insoluble solid particles from a liquid?
A. Magnet
B. Filter paper
C. Thermometer
14. During filtration of muddy water, the mud left on the filter paper is called:
A. Solvent
B. Vapour
C. Residue
15. During filtration, the liquid collected below the funnel is called:
A. Filtrate
B. Residue
C. Sediment
16. Which method is best to obtain sugar crystals from sugar solution?
A. Handpicking
B. Evaporation
C. Using a magnet
17. Small stones mixed with rice can be removed by:
A. Evaporation
B. Filtration
C. Handpicking
18. Which property helps to separate iron filings from sand?
A. Iron is attracted by a magnet
B. Sand dissolves in oil
C. Iron turns into water
19. Why can lemonade taste more or less sweet at different times?
A. It is always a pure element
B. The amount of sugar can vary
C. It has no water
20. Which comparison is correct?
A. Pure substance: variable composition; Mixture: fixed composition
B. Pure substance: always visible parts; Mixture: only one particle
C. Pure substance: fixed composition; Mixture: variable composition