1. Chemistry Department Waid Academy Unit 1 Chemical Reactions

2. Which choice shows something that always happens in a chemical reaction? 1.A gas is given off. 2.Heat energy is absorbed 3.A new substance is formed. 4.A colour change occurs. 15

3. In a precipitation reaction 1.two solutions are mixed and a gas is given off. 2.two solutions are mixed and there is a colour change. 3.two solutions are mixed and heat energy is given out. 4.two solutions are mixed and an insoluble solid is formed. 15

4. Chips cook faster than boiled potatoes due to the chips 1.having a smaller surface area and cooking at a lower temperature. 2.having a larger surface area and cooking at a lower temperature. 3.having a larger surface area and cooking at a higher temperature. 4.having a smaller surface area and cooking at a higher temperature. 15

5. Which of the following is not a chemical reaction? 15 1.A match burning. 2.Water boiling in a kettle 3.Frying an egg 4.Glue setting

6. A catalyst is a substance which 15 1.speeds up reactions involving only gases. 2.speeds up reactions involving only liquids. 3.speeds up some reactions and is used up in the reaction. 4.speeds up some reactions and is not used up in the reaction.

7. What name is given to a catalyst affects living things? 1.A precipitate. 2.Platinum. 3.A converter. 4.An enzyme. 15