1. When sugar dissolves in warm water, the water is called..
A. a solute.
B. a solvent.
C. a dissolvant.
D. a dissolute.
2. Sugar dissolves in water easily. This process is..
A. a chemical change because atoms have been rearranged in a reaction.
B. a physical change because atoms have been rearranged in a reaction.
C. a chemical change because NO atoms have been rearranged in a reaction.
D. a physical change because NO atoms have been rearranged in a reaction.
3. The sugar can be recovered from the water by..
A. filtering the water.
B. chromatography.
C. evaporating the water.
D. diffusion.
4. Which of these sentences best describes if sugar water is a pure or impure substance?
A. Pure substance as no other chemicals have been added to the salt water.
B. Pure substance as all the molecules are the same.
C. Impure substance as there are several different elements in the sugar water.
D. Impure substance as there are 2 types of molecules present.
5. Some water in a container used for camping is found to have some sand and other dirt particles in it. What is the simplest method to remove these insoluble particles?
A. filtering the water.
B. chromatography.
C. evaporating the water.
D. diffusion.
6-8. Some red food colouring is added to a beaker containing hot water. The red colour slowly spreads throughout the water as shown here:
6. What is the name given to this process?
A. Dispersion.
B. Diffraction.
C. Distillation.
D. Diffusion.
7. How does this process happen?
A. The particles spread from a small region of low concentration to a larger region of high concentration.
B. The particles spread from a small region of high concentration to a larger region of low concentration.
C. The particles spread from a large region of high concentration to a smaller region of low concentration.
D. The particles spread from a large region of low concentration to a smaller region of high concentration.
8. Complete the following sentence:
If the water is cooler, the red colour will spread
.
9-10. The image shows some inks separating out as water spreads upwards through some filter paper:
Key:
1 = water
2 = filter paper
3 = black ink dot
4 = coloured ink dots
5 = water 'front' moving upwards
6 = pencil 'start' line
9. What is the name given to this process of separating chemicals?
A. Filtering.
B. Chromatography.
C. Distillation.
D. Diffusion.
10. Why is pencil used as the bottom line?
A. It makes it easier to see.
B. The graphite markings from the pencil are not soluble in water.
C. The graphite markings from the pencil diffuse easily.
D. The graphite markings from the pencil are made of several ink colours.
