Reaction rates

What is rate of reaction?

Change in concentration of a reactant or product per unit of time

= how quickly are reactants being used up or products are being formed

What is neccessary for a reaction to occur?

Particles must collide with enough energy (same as activation energy or more) and the correct orientation

Why does increasing temperature increase reaction rate?

Higher concentration increases the kinetic energy which makes the particles faster and therefore the chance of successfully colliding with a greater amount of energy increases as well

Why does increasing concentration increase rate of reaction?

More particles are in the same area/volume so the likelihood of particles colliding and running into one another grows —> more collisons per second

Why do smaller particles react faster?

They have a bigger surface area allowing more collisions

How do you calculate the average rate of reaction?

change in y (measured quantity) / change in x (time)

How do you find the rate at a specific point on a graph?

1) You draw a tangent at that point

2) Choose 2 points on the tangent

Calculate gradient using: Δy / Δx

What does a Maxwell-Boltzmann distribution show?

How the kinetic energy of particles are distributed at a given temperature

Do all particles in a sample have the same kinetic energy?

No. Their speeds and therefore kinetic energy vary. Mass however is the same.

What is activation energy?

The minimum amount of energy particles have to carry for a reaction to occur.

Why does a catalyst increase the reaction rate?

It lowers the activation energy, so more particles are able to react since less energy is needed

How do you calculate the rate of reacrtion?

Amount of reaction used / time —> always measure change per unit of time

How do you calculate the amount of gas produced as the reaction takes place?

Rate of reaction = amount of product produced / time

What is meant by yield?

Yield: is the number of something produced