9. Kinetics I

Question 1

Give the conditions for a chemical reaction to occur by collision theory

Answer 1

-Particles collide
- collide in the right direction/orientation
- collide with the minimum activation energy

Question 2

Define activation energy

Answer 2

The minimum energy which particles need to collide and start a reaction

Question 3

Describe the maxwell Boltzmann distribution graph

Answer 3

starts at 0 as no particles have no energy
Y axis - number of particles with this energy
X axis - Energy

Question 4

How does increasing temperature increase rate of reaction

Answer 4

increases rate
- increasing temperature means reactant particles will have a greater kinetic energy and will move faster with a greater proportion of particles having the minimum activation energy

Question 5

Describe how the maxwell boltzmann distribution graph would change with increased temperature

Answer 5

Peak sits to the right
Peak is lower
Area under the curve remains the same
Area under curve beyond activation energy increases

(opposite is true for lower temperature)

Question 6

Describe how increasing concentration impacts rate

Answer 6

more particles in a given volume so collisions are more frequent and higher chance for a collision with the minimum activation energy

Question 7

Explain how a catalyst works

Answer 7

A catalyst provides an alternative pathway with a lower activation energy

Question 8

Define heterogenous catalyst

Answer 8

Catalyst is in a different physical state to the reactants. Eg: its a solid and all other reactants are gasses.
–> these solid catalysts provide a surface for the reaction when all reactants are gasses

Question 9

Describe how heterogenous catalyst provide a surface for a reaction (how do they work)

Answer 9

Reactants adsorb on to the surface of the catalyst at active sites.
Reaction takes place which weakens bonds
Product is desorbed

Question 10

Define homogenous catalyst

Answer 10

Catalyst is in the same physical state to other reactants