Collision Theory

Question 1

More collisions, has what effect on the rate of reaction?

Answer 1

More collisions, quicker rate of reaction.

Question 2

What happens to the particles when the temperature is increased?

Answer 2

The particles move around quick because they’ve got more energy, if they’re moving quicker, they’re going to collide more often, thus increasing the frequency of collisions and increasing the rate of reaction.

Question 3

What happens to the particles when the concentration is increased?

Answer 3

If a solution is more concentrated, more particles of the reactant are present in the solution, therefore more particles are available to react, increasing the frequency of collisions and the rate of reaction.

Question 4

What happens to the particles in a gas when the pressure is increased?

Answer 4

The gas particles are more squished together, therefore they’re more likely to collide when there’s high pressure, increasing the frequency of collisions, therefore increasing the rate of reaction.

Question 5

What happens to the particles when the surface area of a reactant is increased?

Answer 5

Because the surface area is increased, more of the reactant particles are exposed to the other reactant, therefore the frequency of collisions increases and so does the overall rate of reaction.
The particles in the solution have more area to work on due to the larger surface area of the solid.

Question 6

What is meant by the term activation energy?

Answer 6

The activation energy is the minimum amount of energy required by the particles for them to react.

Question 7

What do catalysts do the rate of reaction?

Answer 7

Quicken it.

Question 8

Define a catalyst.

Answer 8

A substance which speeds up a reaction without being used or changed during the reaction.

Question 9

How do catalysts help industries save money? 2 ways.

Answer 9

Because they quicken the rate of reaction, the plant/machine that carries out an industrial reaction doesn’t need to operate for as long; the catalyst means that money on energy bills is saved.
Catalysts allow a reaction to take place at a much lower temperature, again this helps companies to save money on heat energy bills.
They’re also never used up.

Question 10

Name the disadvantages of catalysts.

Answer 10

• Expensive
• They have to be maintained, removed from the product and cleaned.
• Catalysts can be poisoned by impurities (tainted), so that they don’t work again
• Different reactions require the purchasing of different catalysts.