Calderglen High School Rates of Reaction 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Calderglen High School

Calderglen High School 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

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

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

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

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

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

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

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 (when the line flattens out and no more gas is produced) Calderglen High School

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 Calderglen High School

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

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

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 150C 2g of small chalk lumps A 2M hydrochloric acid at 150C 2g of small chalk lumps B 2M hydrochloric acid at 250C answer 1M hydrochloric acid at 250C 2g of small chalk lumps D C 2g of large chalk lump 2M hydrochloric acid at 250C Calderglen High School

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

A B C D answer 2M hydrochloric acid at 250C 2g of small chalk lumps 2g of large chalk lump C 1M hydrochloric acid at 250C 2g of small chalk lumps D Calderglen High School

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

A B D C answer 2M hydrochloric acid at 250C 2g of small chalk lumps 2g of large chalk lump C Calderglen High School

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

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). Calderglen High School

18. Which colour of line shows the fastest rate of reaction? RED LINE Steeper gradient Calderglen High School

Calderglen High School 19. What could you measure in this experiment to work out the rate of reaction? Marble + Acid  Salt + Water + Carbon dioxide Change in mass Volume of gas produced Calderglen High School