Factors that affect equilibrium

Question 1

What is Collision Theory?

Answer 1

Collision theory states that for a successful collision to occur, the collision must collide at the correct orientation, and sufficient speed (ideally above the activation energy). A collision must occur above the activation energy, which is defined as the minimum energy required to start a chemical reaction, as the particles won’t react with each other to form the products.

Question 2

Describe collision theory in terms of the translational energy and kinetic energy manifested within.

Answer 2

The kinetic energy levels of reacting particles must be high enough to break the bonds so that that the particles become free to make new bonds as they arrange in a chemical reaction.

Question 3

Explain in terms of collision theory the effect of increasing Concentration

Answer 3

In a system at equilibrium, there is an increased number of collisions between reactant particle, when the concentration of the reactants is increased. Initially, since there was no change to the product concentration, the rate of the reverse reactions remains the same.
However, as new product particles form due to the increased rate of the forward reaction, the rate of the reverse reaction also increases as the conc of products increase. Over time, A new equilibrium re-establishes where the reverse and forward reaction rates are equal. The equilibrium will have shifted to the right in response to an increase in conc. of reactant molecules.

Question 4

Explain in terms of collision theory the effect of increasing temperature

Answer 4

• Increasing temperature increases the rate of any reaction, as the proportion of particles with enough energy to overcome the activation energy increases and the collisional frequency increases.
• Increasing temperature favours the endothermic reaction

Question 5

Explain the effect of increasing the pressure in a one-to-one ratio.

Answer 5

An increase in pressure is a decrease in volume. If pressure is increased, both reactant and product molecules are closer together, hence will collide more frequently. Thus the forward and reverse rates of reaction will increase.

Question 6

Effect of pressure on different moles

Answer 6

However, if one sides has more moles of gas, there will be more frequent collisions amongst this side.
The equilibrium shifts to the side with fewer moles of gas.

Question 7

Example - explain how to increase the yield of ammonia with reference to collision theory.

Answer 7

Since Ammonia is exo, it favours the reverse reaction when temp is increased.
1. Catalyst - alternate pathway with a lower activation energy provided, hence by CT, the rate of reaction increases as a greater proportion of particles have sufficient energy.
2. Derease in temp
3. Increase in pressure - favour the forward - as there are less moles of gas on the products side (4:2 ratio)
4. Removal of NH3 will increase the production