1.1 Rates of Reaction

Question 1

What factors affect the rate of chemical reaction?

Answer 1

Temperature.
Concentration.
Particle Size.
Catalyst.

Question 2

What happens if you increase the temperature in a reaction?

Answer 2

Increasing the temperature increases the energy of the particles making
them move faster and so more successful collisions can occur.

Question 3

What happens if you increase the concentration in a reaction?

Answer 3

If the concentration is increased, there are more atoms present, and as a
result more collisions take place.

Question 4

What happens if the particle size is reduced in a reaction?

Answer 4

If the particle size is reduced (the reactants are broken into smaller pieces)
then the rate of the reaction is increased. This is because a small particle
size results in a large surface area meaning that collisions will happen
more frequently.

Question 5

What happens if you add a catalyst to a reaction?

Answer 5

Catalysts are used a lot in industry as they allow reactions to be
performed at a lower temperature, which saves energy and money. They
also increase the rate of the reaction. Platinum and other transition
metals are used in car exhaust systems to convert harmful gases into less
harmful gases.

Question 6

What is the formula to calculate the rate of reaction?

Answer 6

rate = change in volume or mass
___________________________

               change in time

Question 7

How can you tell if a reaction has finished?

Answer 7

The point on the graph when the line becomes flat (horizontal) is
called the end-point (shown by the dotted line). This is because there is
no longer any gas being produced, therefore the reaction has stopped.
Generally the rate of a reaction slows as it progresses because the
reactants are being used up.