rates of reaction

Question 1

What does it mean by “rate of reaction”?

Answer 1

-how fast reactants are changed to products

Question 2

what are the two ways rate of reaction be calculated?

what are the 3 units for rate of reaction?

Answer 2

mean rate of reaction = quantity of reactant used/time taken
or
mean rate of reaction = quantity of product formed/time taken

units= g/s or cm^3/s or (HT ONLY mol/s)

Question 3

On a graph- what does the gradient of the tangent to the curve show?
the steeper the gradient..?

Answer 3

• the gradient of the line is the measure of the rate of reaction.
• the steeper the gradient the faster the reaction.

Question 4

to calculate the rate of reaction at a specific time on a graph- what do you do?

Answer 4

draw a tangent at the point!!

and calculate gradient :)

Question 5

What are the 5 factors that can affect the rate of chemical reactions?

-rate your card by how many you get out of five!

Answer 5

• temperature
• presence of catalyst
• surface area of solid reactants
• pressure of reacting gases
• concentration of solution

Question 6

how does temperature affect rate of reaction?

Answer 6

-increasing temperature increases reaction- particles collide more often, particles collide with more energy

• temperature increase= more kinetic energy store of particles
• more collisions occur- more frequently per second
• as they collide with higher energy, there are more effective, successful collisions to make reaction happen

Question 7

How does surface area affect the rate of chemical reaction?

Answer 7

• increasing surface area = smaller pieces of solid piece
• increases surface area to volume ratio
• more particles are exposed to reaction
• more frequent collisions between reacting particles

Question 8

How does concentration affect rate of reaction?

Answer 8

-higher concentration = more particles in a given volume
-more particles= increases frequency of collisions
-effective collisions increase
therefore, rate of reaction increase

Question 9

how does pressure affect rate of reaction?

Answer 9

• higher pressure=same number of particles in a smaller given space
• frequency of collisions increased
• effective collisions also increase
• therefore, rate of reaction increases

Question 10

how do catalysts affect rate of reaction?

Answer 10

-speed up reaction without being used up

• decrease activation energy for a reaction to happen
• provide an alternate reaction pathway with lower activation energy
• higher proportion of reactant particles have sufficient energy to react
• frequency of collisions increases.

Question 11

activation energy graph with and without catalyst

Answer 11

https://www.google.com/search?q=activation+catalys+graph&tbm=isch&ved=2ahUKEwi6_undt7L4AhVCrhoKHdR1DW4Q2-cCegQIABAA&oq=activation+catalys+graph&gs_lcp=CgNpbWcQAzIICAAQHhAIEAcyCAgAEB4QCBAHMggIABAeEAgQBzIICAAQHhAIEAc6BAgjECc6BggAEB4QCFDuA1ipCmDRDWgAcAB4AIABeIgB_AGSAQMyLjGYAQCgAQGqAQtnd3Mtd2l6LWltZ8ABAQ&sclient=img&ei=I2CrYvrgMcLcatTrtfAG&bih=694&biw=1517&rlz=1C1CHBF_en-GBGB893GB893&hl=en-GB

Question 12

where are catalysts used?

advantage + disadvantage?

Answer 12

• in industry
• A: increases rates + reduces energy costs
• A: helps environment- using lower temperature
• D: expensive- buttt cheaper to use catalsyt than pay for extra energy

Question 13

What is the collision theory?

Answer 13

• chemical reactions can only occur when reacting particles collide with each other with sufficient energy

Question 14

What is activation energy?

Answer 14

-the minimum amount of energy needed for particles to react

Question 15

1. What to do to make a reaction happen faster?

2. to increase rate of reaction?

Answer 15

1.reduce activation energy

2. increase frequency of particle collisions
   increase energy of particles when colliding