GCSE Chemistry rates of reaction - catalysts - Phoenix Hoyle | Library

1

Reactions occur when particles ____________  and that rates of reaction are increased when the ______________  and / or energy of collisions is increased.

Other Answer Choices:

frequency

collide

3

Increasing concentration means that there are __________ particles in a given ___________ . This means that the collision ______________ increases so the rate of reaction increases. 

Other Answer Choices:

volume

frequency

more

3

Increasing pressure means that there are __________ particles in a given ___________ . This means that the collision ______________ increases so the rate of reaction increases. 

Other Answer Choices:

volume

more

frequency

2

Decreasing the size of solid samples e.g. from granule to powder means that the surface _________to volume ratio ______________ , therefore there are more particles of the solid that are available for collisions so collision ______________increases and the rate of reaction increases.  

Other Answer Choices:

area

increases

frequency

4

Increasing temperature means that there the particles  move more ____________  so they collide more _______________they also have more kinetic energy so they collide more _______________both of these factors _____________  so the rate of reaction.

Other Answer Choices:

forcefully

quickly

frequently

increase

3

A catalyst as a substance that ___________  up the rate of a reaction without altering the products of the reaction, being itself ______________  chemically and in mass  at the end of the reaction

Other Answer Choices:

unchanged

speeds

1

Explain how the addition of a catalyst increases the rate of a reaction by providing an ________________ reaction route of __________  activation energy.

Other Answer Choices:

alternative

lower

5

1

Recall that enzymes are _______________  catalysts and that enzymes such as __________ are used in the production of alcoholic drinks. 
Note enzymes work best at moderate temperatures as ___________  temperatures denature the ___________while __________  temperatures would cause the collision frequency to be decreased and mean that fewer collisions can exceed the activation energy.

Other Answer Choices:

lower

yeast

higher

biological

enzyme

3

Recall the conditions for the Haber process as: 
a temperature ________  °C 
b pressure ________  atmospheres 
c _________  catalyst

Other Answer Choices:

450

200

iron

1

_______ 

1

What is the rate of reaction at 3 minutes

_______ cm3 / s

1

What is the rate of reaction at 8 minutes

_______ cm3 / s

1

What is the rate of reaction at 4 minutes
Rate = _______ cm3/s

	Increases collision frequency	Increases the proportion of the collisions that exceed the activation energy
Concentration increase
Temperature increase
Adding a catalyst
Making solids finer grained

	Increases collision frequency	Increases the proportion of the collisions that exceed the activation energy
Concentration increase
Temperature increase
Adding a catalyst
Making solids finer grained