Chemical Kinetics (Topic R2.2)

What is collision Theory?

The idea that particles must collide with greater kinetic energy than the activation energy, and must have the correct collision geometry for a reaction to occur.

What is Activation energy?

minimum kinetic energy needed for a reaction to occur

What is the transition state?

the top of the energy profile, where an unstable species is formed before the product

What is the relationship between kinetic energy and temperature?

Avg kinetic energy is proportional to temperature in kelvin

What is the Kinetic theory of matter?

all matter has constant motion particles, and the kinetic energy for gases>liquids>solids.

What is the reaction mechanism in kinetic theory?

a sequence of bond breaking and creation which suggests how a reaction occurs

What are the 5 factors that influence rate of reaction?

Pressure, surface area, concentration, temperature, catalysts

How does pressure influence rate of reaction?

higher pressure results in higher densities of particles, which increases the chance of collisions with the correct orientation, and thus increases rate of reaction

How does Surface Area influence rate of reaction?

Greater surface area results in greater area in which collisions can occur, and thus increases the rate of reaction

How does concentration influence rate of reaction?

Greater concentration of particles means that there is a larger no. of particles that are able to react, which means there is a higher chance of correct geometry collisions to occur, and thus increases the rate of reaction

How does temperature influence rate of reaction?

A greater temperature causes particles to have a higher kinetic energy, and thus increases the chance that a reaction with sufficient energy will occur, which increases the rate of reaction

How does the presence of a catalyst influence rate of reaction?

A catalyst provides an alternative reaction pathway, which helps facilitate collisions with the correct energy and orientation and/or lowering the activation energy, which causes the rate of reaction to increase

What is the Maxwell-Boltzmann curve?

A graph showing the distribution of particles, and their likelihood of having a successful reaction. Changes in rate of reaction change the curve’s shape.