Rate of reaction

Question 1

What does a catalyst do?

Answer 1

increases the rate of the reaction

Question 2

Is a catalyst changed in a reaction?

Answer 2

no, it is unchanged at the end of the reaction

Question 3

How does a catalyst speed up a reaction?

Answer 3

by providing an alternative pathway with a lower activation energy

Question 4

What is the effect of increasing concentration on the rate of reaction? Why?

Answer 4

• increases rate of the reaction
• number of reactant particles increases
• increased chance of successful collisions

Question 5

What is the effect of increasing pressure on gases on the rate of reaction? Why?

Answer 5

• increases rate of reaction
• number of particles in a given volume increases
• increased chance of successful collisions

Question 6

What is the effect of increasing surface area of solids on the rate of reaction? Why?

Answer 6

• increases rate of reaction
• when solids react, it occurs on substance surface
• more surface area exposed

Question 7

What is the effect of increasing the temperature on the rate of reaction? Why?

Answer 7

• increases rate of reaction
• particles gain more kinetic energy, move faster
• particles collide more often
• more chance of a successful collision

Question 8

What must occur for a ‘successful’ chemical reaction to take place?

Answer 8

• particles must collide
• collide with correct orientation
• collide with sufficient KE

Question 9

In collision theory, what is the relationship between concentration and RoR?

Answer 9

directly proportional

Question 10

In collision theory, what happens to the RoR when particles get a higher KE?

Answer 10

particles with more energy mean more collisions are successful, increasing collision rate

Question 11

What is activation energy?

Answer 11

the minimum energy requires for a reaction to happen

Question 12

What happens if particles collide more frequently with each other?

Answer 12

more collisions are successful, increases RoR

Question 13

What are 2 ways to investigate the rate of reaction?

Answer 13

1. change in mass of a reactant/product
2. formation of a gas

Question 14

experiment to measure rate of reacttttiiiiooonn

Answer 14

• Set up a conical flask and gas syringe
• Place 1 g of medium marble chips into the conical flask (calcium carbonate)
• Add 50 cm3 of 1 mol/dm3 hydrochloric acid and quickly replace the bung.
• Start the stopwatch and every 15 seconds record the volume of carbon dioxide gas formed.
• Stop when no more gas is being produced.