Revision Questions Pg. 52 to 55
Thursday, February 19, 2009
Pg. 52
1. A 2. A 3. C 4. D 5. B
Pg. 53
2a) Compound; It is broken down into simpler substances when heated.
b) Carbon dioxide; it is a compound of carbon and oxygen.
c) Copper oxide: Black; solid at room temperature
Copper : Reddish brown, shiny solid
Oxygen : Colourless; Gas at room temperature
3ai) Copper + chlorine --> Copper chloride
Or
Nitrogen + oxygen --> Nitrogen oxide
ii) Nitrogen oxide + oxygen --> Nitrogen dioxide
iii) Ammonia + Hydrogen chloride --> Ammonium chloride
b) Nitrogen oxide / nitrogen dioxide - nitrogen, oxygen
Ammonia - nitrogen, hydrogen
Hydrogen chloride - hydrogen, chlorine
Ammonium chloride - nitrogen, hydrogen, chlorine
Copper chloride - Copper, chlorine
c) All of the above in (b).
4a) Metal
b) It can used as an electrical wire.
c) It is a compound as it is formed from 2 elements in a chemical reaction.
5. The white solid is a compound because it breaks down into simpler substances when heated. However, we cannot conclude that the colourless liquid is an element because it could have been broken down into simpler substances by other chemical methods, for example, by passing an electric current through it.
