Kinetics

Question 1

Define the term rate of reaction.

Answer 1

the decrease in the concentration of reactants per unit time, or the increase in the concentration of product per unit time.

Question 2

Unit for rate in SI?

Answer 2

mol dm^-3 S^-1

Question 3

Name 6 ways to measure rate of reaction.

Answer 3

1. Change in volume of gas produced.
2. Change in mass.
3. Change in transmission of light
4. Change in concentration measured with titration
5. Change in concentration measured using conductivity
6. Non continuous methods of detecting change: ‘clock reactions’

Question 4

Describe how to measure the change in volume gas produced.

Answer 4

Graph = volume vs time
A gas syringe can be calibrated to record the volume directly. If a gas syringe is not available then gas can be collected by displacement of water in an inverted burette or measuring cylinder. Use warm water.

Question 5

Describe how to measure change in mass.

Answer 5

Final minus initial. There is lots of subtraction.

Question 6

Describe how to measure the change in transmission of light.

Answer 6

You can use an indicator. And then your eyes.

Question 7

Describe how to measure Change in concentration measured with titration

Answer 7

through titration. i really don’t feel like reading it sorry.

Question 8

true or false:

increasing temperature means an increase in the average kinetic energy.

Answer 8

TRUE

Question 9

What is the Maxwell-Boltzmann curve

Answer 9

expresses that particles in a gas at a PARTICULAR TEMPERATURE show a range of values of kinetic energy

Question 10

What does the collision theory state?

Answer 10

In oder for a successful reaction the right orientation (geometry) and the right amount of energy is needed

Question 11

Why is activation energy needed?

Answer 11

Gives the molecules energy to overcome their repulsion to one another. Particles must collide with energy greater than the activation energy.

If particles do not have kinetic energy greater than the activation energy and they collide then a reaction does NOT happen.

Question 12

What factors affect rate of reaction?

Answer 12

Any factor that increases the number of collisions will increase the rate of the reaction.

These are:

1. Temperature (higher the better)
2. Concentration (the more the better [to a point])
3. Particle Size (smaller the better)
4. Pressure (if it involves gases then the higher the bettah)
5. Catalyst (lowers activation energy).