Revision Questions Pg. 60 to 64
Thursday, February 19, 2009
Pg. 60
1. B 2. D 3. B 4. C 5. D
Pg. 61
1a) Sugar : Constituents are combined during chemical reactions in fixed proportions by mass;
Sugar solution : Constituents do not combine in a fixed proportion and do not have to go
through chemical reactions to form sugar solution.
b) Little / no energy is exchanged with surroundings during its formation;
Constituents can be separated by physical methods;
Mixture has the properties of its constituents.
c) Simple Distillation
2. - Add water to the gardening mixture and stir.
- Wait for some time to let the mixture settle.
- The sawdust will float on the surface of the water and it can be removed and dried.
- The remaining mixture can be filtered. Calcium carbonate will remain as the residue.
- The potassium nitrate solution is the filtrate.
- The filtrate is evaporated to remove the water. Potassium nitrate is left behind as the
residue.
3a) Simple distillation
b) A - Condenser
B - Outlet for water
C - Inlet for water
c) No. The boiling point of water is 100 degree celsius.
d) D - distillate; Liquid - alcohol
4a) Elements : Nitrogen, oxygen, argon, neon, krypton
Compounds : Carbon dioxide, water
b) The constituents of air do not combine in fixed proportions.
c) Fractional distillation of liquid air is used. The difference in the boiling points of the constituents of liquid air is used to separate them.
5a) A solvent (eg. water / alcohol) is used. The food dyes, together with the solvent, will move up the filter paper but a different rates because some of the dyes move faster than others.
The dyes that hold on to th surface of the filter paper move solwer. The different dyes are thus spread out and separated into different components on the paper.
b) B, C, D
c) Yes. There is a matching spot of food dye C and the food colouring on the chromatogram.
