Calderglen High School 17 16

1.Describe how the concentration of reactants affects the speed of reaction? As the reactant concentration increases the speed of the reaction increases. Calderglen High School

2. Name FOUR factors which affect the speed (or rate) of a chemical reaction? Particle Size (Surface Area) Temperature Concentration Use of Catalyst

Calderglen High School 3. Draw a line to show the results if a higher temperature is used? Steeper gradient Steeper gradient Same final result (volume) Same final result (volume)

Calderglen High School 4.Describe how particle size affects the speed of reaction? As particle size decreases the As particle size decreases the speed of reaction increases speed of reaction increases

Calderglen High School 5. Describe how temperature affects the speed of reaction? As temperature increases the speed of reaction increases As temperature increases the speed of reaction increases

Calderglen High School 6.What are ENZYMES? Biological catalysts Biological catalysts

Calderglen High School 7.What is a catalyst? A substance which can speed up a reaction, but is not used up in the reaction and can be recovered chemically unchanged

Calderglen High School 8.Why does decreasing the particle size of reactants increase the speed of reaction? Smaller particles give a bigger surface area. This results in more collisions between reactants and therefore faster reactions

Calderglen High School 9. What time did the reaction finish at? 45 seconds 45 seconds (when the line flattens out and no more gas is produced) (when the line flattens out and no more gas is produced)

Calderglen High School 10.What must be controlled when carrying out experiments to compare speeds of reaction? All variables other than the one being tested must be kept the same in all experiments All variables other than the one being tested must be kept the same in all experiments

Calderglen High School 11.What is a VARIABLE? Any factor in an experiment which can be changed or varied. e.g. concentration or temperature Any factor in an experiment which can be changed or varied. e.g. concentration or temperature of the solution used of the solution used

Calderglen High School 12.Give everyday examples of uses of catalysts? Transition metals in car catalytic converters.

Calderglen High School 13.Rates Experiments Which two of the following experiments could be used to find the effect of changing the particle size?

Calderglen High School 2M hydrochloric acid at 25 0 C 2g of large chalk lump 2g of small chalk lumps A 2M hydrochloric acid at 15 0 C 2g of small chalk lumps B C 1M hydrochloric acid at 25 0 C 2g of small chalk lumps D

Calderglen High School 14.Rates Experiments Which two of the following experiments could be used to find the effect of changing the concentration of the acid?

Calderglen High School 2M hydrochloric acid at 25 0 C 2g of small chalk lumps A 2M hydrochloric acid at 15 0 C 2g of small chalk lumps B 2M hydrochloric acid at 25 0 C 2g of large chalk lump C 1M hydrochloric acid at 25 0 C 2g of small chalk lumps D

Calderglen High School 15.Rates Experiments Which two of the following experiments could be used to find the effect of changing the temperature of the acid?

Calderglen High School 2M hydrochloric acid at 25 0 C 2g of small chalk lumps A 2M hydrochloric acid at 15 0 C 2g of small chalk lumps B 2M hydrochloric acid at 25 0 C 2g of large chalk lump C 1M hydrochloric acid at 25 0 C 2g of small chalk lumps D

Calderglen High School 16.What does EXOTHERMIC mean? Heat energy is given out in a reaction.

Calderglen High School 17.Two chemical react in a test tube. The temperature goes down. Is the reaction EXOTHERMIC or ENDOTHERMIC? ENDOTHERMIC (heat energy is taken in by the reaction, this makes the surrounding temperature fall).