Chapter 5 - Kinetics Flashcards
What is collision theory?
It is the idea that particles can only react once they have collided with sufficient energy?
What is the “sufficient energy” referred to in collision theory?
It is also known an activation energy, and it refers to the amount of energy required to break the bonds present in a molecule before it can react
What is the Maxwell-Boltzmann distribution curve?
The Maxwell-Boltzmann curve is the curve which depicts the amount of particles with a specific amount of energy at temperature, and shows the average kinetic energy of the particles and also the fact that some particles will have energy both above and below the mean energy, and some will have enough energy to react (greater than the activation energy)
What happens on the curve if the energy of the system is increased?
The peak of the mean energy will flatten slightly and it will take longer for the highest amount of energy to plateau, therefore more molecules will have the required activation energy so the reaction will happen faster
And what if it is decreased?
If the energy is decreased more molecules will have the mean energy, and less molecules will have higher amounts of energy, therefore less molecules have activation energy so the reaction will happen more slowly
Define rate of reaction
Rate of reaction is the speed at which a reaction occurs, and a large part of it is determined by the reactivity of the reactants, however it can be sped up or slowed down by its conditions
What is the formula for rate of reaction?
Rate of reaction = amount of product formed / time taken OR amount of reactant used / time taken
What does increase in concentration cause in terms of rate of reaction?
As there are more molecules present, it will increase the rate of reaction. However as the reaction continues the reactants will be used up so it will decrease as the reaction continues as less and less successful collisions will occur
How does an increase in the pressure of a gas affect the rate of reaction?
The increase in pressure means the volume of the container has been decreased, so more molecules will be collding more freqeuntly so the rate of reaction will increase
What is a catalyst?
A catalyst is a substance which reduces the activation energy of a reaction by providing an alternative route of reaction which requires less energy. It is unchanged by the end of reaction, or regenerated
