Rates of Reaction

What is collision theory?

• Chemical reactions can only take place when the reacting particles collide with each other

• The collisions must have sufficent energy

• The rate of a chemical reaction is determined by the frequency of successful collisions per second

What is frequency?

the number of successful collisions per second

How does concentration of particles in a gas correlate with rate of reaction?

The higher the concentration of particles in a gas, the higher rate of reaction

How does surface area of a solid correlate with rate of reaction?

When the surface area increases, the rate of reaction increases

What is the surface are to volume ratio for smaller sized blocks?

• they have a greater surface area to volume ratio than larger blocks

• as more particles on the surface so more collisions per second

• increasing the rate of reaction

How does temperature correlate with the rate of reactions?

Increasing the temperature, means a higher rate of reaction

How do catalysts affect the rate of reaction?

• They increase the rate of reaction by providing a different pathway for the reaction that has a lower activation energy

• so particels require less energy to cross the activation energy barrier

What are enzymes?

Biological catalysts

What’s the equilibrium point?

When the forward and the reverse reactions will take place at exactly the same rate

What is Le Chatelier’s Principle?

If a system is at equilibrium and a change is made to the conditions, then the system responds to counteract the change

What is a reversible reaction?

When the products can react to form the orginial reactants

How can you change the direction of reversable reactions

changing the conditions

What are the properties of reversible reactions?

the same amount of energy is transferred

What is the effect of chaning conditions on equilibrium?

• if a system is at equilibrium and a change is made to the conditions

• the system responds to counteract the change

What is the rule with pressure in a reversible reation?

• if pressure increases

• position of equilbrium shifts to the side with smaller numebr of molecules