(U2) Kinetics

Question 1

What is reaction rate? (2)

Answer 1

• The change of the concentration (amount) of a reactant or product
• with respect to time

Question 2

What is a catalyst? (2)

What does it do?

Answer 2

1.

• A substance which increases the rate of a chemical reaction
• but does not get used up

2.

• provides an alternate reaction pathway with lower activation energy

Question 3

What is activation energy?

Answer 3

The minimum amount of energy required for a reaction to occur

Question 4

In terms of particles, how does concentration affect the rate of a reaction? (5)

Answer 4

• increased concentration increases rate of reaction
• more acid particles in the same volume
• more chance of collisions
• resulting in more successful collisions
• in a given time

Question 5

In terms of particles, how does pressure affect the rate of a reaction? (5)

Answer 5

• increased pressure increases rate of reaction
• more particles in the same volume
• more chance of collisions
• resulting in more successful collisions
• in a given time

Question 6

In terms of particles, how does surface area affect the rate of a reaction? (5)

Answer 6

• increased surface area increases rate of reaction
• more particles on the surface exposed to the other reactant
• more chance of collisions
• resulting in more successful collisions
• in a given time

Question 7

In terms of particles, how does Temperature affect the rate of a reaction? (6)

Answer 7

• increased temperature increases rate of reaction
• particles gain kinetic energy
• particles move faster
• more chance of collisions
• resulting in more successful collisions (enough activation energy)
• in a given time

Question 8

What is the steric factor for molecules bonding?

Answer 8

particles must approach with the correct orientation to react on collision

(also need activation energy)

Question 9

What does the area under a Maxwell-Boltzmann distribution curve represent?

Answer 9

The total number of molecules present

Question 10

Why does a Maxwell-Boltzmann distribution curve start at the origin?

Does it touch the x axis anywhere else?

Answer 10

• No molecules have no energy
• no

Question 11

Where is activation energy on a Maxwell-Boltzmann distribution curve?

left or right?

Answer 11

To the right hand side

Question 12

Where is the most likely energy on a Maxwell-Boltzmann distribution curve?

Answer 12

Just to the right of the greatest peak