Simple collision theory

Question 1

What is rate of reaction?

Answer 1

• ROR measures how fast a reactant is being used up or how fast a product is being used up

Question 2

What is the equation for ROR?

Answer 2

change in conc/time

Question 3

What are the changes in ROR over a reaction?

Answer 3

• the ROR is the fastest at the start of the reaction, as each reactant is at its highest concentration
• The ROR slows down as the reaction proceeds, because the reactants are being used up and their concentration decreases
• Once the reactants are completely used up, the conc stops changing and the rate is 0

Question 4

How can you alter the rate of a reaction?

Answer 4

You can do this by changing:
- concentration
- temperature
- the use of a catalyst
- the SA of solid reactants

Question 5

What is the collision theory?

Answer 5

In order for a reaction to occur, particles need to react with a sufficient amount of energy and at a correct orientation

Question 6

How does increasing the concentration affect the ROR?

Answer 6

• when you increase conc, you increase ROR
• this is because increasing conc, increases the number of particles in the same volume.
• This means more particles occupy a smaller volume of space
• This means particles are closer and have more chances to collide successfully and more effectively

Question 7

How does increasing the pressure affect the ROR?

Answer 7

• Increasing pressure, decreases the volume that the same concentration of particles occupy
• This means that there is less space and there are more effective collisions
• This means that the particles will collide more frequently

Question 8

What are methods of following a chemical reaction?

Answer 8

• monitoring the removal of a reactant
• monitoring the formation of a product

Question 9

What are methods of following a reaction that produce gas?

Answer 9

• monitoring the volume of gas produced at regular intervals
• monitoring the loss of mass of reactants using a balance