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Topics 7-8 Unit 2
Topics 7-8 Matter and Chemical Change Study Set
Question | Answer |
---|---|
when does a chemical reaction occur? | when one or more substances changes |
what are the substances that go into a chemical reaction called? | reactants |
what are the substances produced by a chemical reaction called? | products |
what are 5 examples of evidence of a chemical change? | formation of a gas, formation of a solid (precipitate), odour change, colour change, energy change |
what is an energy change? | an increase or decrease in certain properties. |
what are examples of properties that increase or decrease as a result of an energy change? | temperature, light, sound, electricity |
what are reactions that release energy called? | exothermic |
what are exothermic reactions caused by? | chemical bonds breaking |
what are reactions that absorb energy called? | endothermic |
what are endothermic reactions caused by? | chemical bonds forming |
what is a reaction rate? | how fast a reaction occurs |
true or false: the rate of a chemical reaction can be sped up or slowed down. | true |
what are 4 ways a chemical reaction's speed can be changed? | changing the temperature, stirring, changing the size of the reactants, changing the concentration of the reactants |
(question XYZ) - true or false: at higher temperatures, the rate of ALL chemical reactions increases | false |
why is (question XYZ) true or false, depending on what you chose? | it is false because at higher temperatures, the rate of MOST chemical reactions increases |
what is another way to change the rate of a chemical reaction? | to add or remove a substance called a catalyst |
what is a catalyst? | a substance that speeds up the rate of a reaction without being changed itself |
does a catalyst affect the amount of product produced in a chemical reaction? If not, what does it affect? If so, the second question doesn't matter. | no, it only affects the speed of a chemical reaction |
what is an enzyme? | a natural catalyst |
what is an inhibitor | substances that slow down chemical reactions |
what is corrosion | the oxidation of metals or rocks the presence of air and moisture |
what is a common example of corrosion | rust |
what is combustion | the highly exothermic reaction between a substance and oxygen |