Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry Rate Of Reactions > Facts In Books > Flashcards

Facts In Books Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Chemistry flashcards Periodic Table flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

How does a catalyst work

A

They lower the activation energy as they provide an alternative pathway at a lower energy level so more successful collisions occur
^^ meaning they speed up reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do catalysts do and not do

A

They speed up reactions but are not used up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the meaning of a reversible reaction

A

A reaction that can be changed back to its original form > the reaction can go in both directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the collision theory

A

In a chemical reaction, reactant particles must collide and the colliding particles must have enough energy for the collision to be successful

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Give 2 ways you can measure the rate of a reaction

A

Amount of reactant used up (divide) time
Or
Amount of product made (divide) time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the effect of temperature on rates

A

If increased the reactant particles move more quickly which means they have more energy and collisions happen more therefore the rate of reaction increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What effect does a catalyst have on a rate of reaction

A

They lower the activation energy, providing a different pathway and a lower energy level so more successful collisions occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What affect does the surface area have on rates of a reaction

A

The fate will increase as more particles are exposed to the other reactant and more collision will therefore happen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the effect of concentration/ pressure on rates of a reaction

A

More reactant particles in same volume so a greater chance for particles to collide and rate increased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the mass of a substances measured with

A

Balance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Volume of a gas is measured with?

A

Gas syringe or burette

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What factored effect rates of a reaction

A 
Temperature change 
Concentration of a dissolved reactant 
Pressure of a reacting gas 
Surface area is changed 
Catalysts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Whats the activation energy

A

The minimum energy needed for particles to react

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does an iron catalyst do

A

Makes ammonia from nitrogen and hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What’s a platinum catalyst effect

A

Making ammonia from nitrogen and hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is bond breaking

A

An endothermic reaction because energy must be supplied to break existing bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is bond formation

A

Exothermic reaction because energy is released when new bonds are formed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How can you calculate the overall energy change for a reaction

A

Using bond energies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What’s the equation for energy change

A

Energy if bond breaking - energy if bond making

20
Q

How do you work out the amount of energy used in bond breaking

A

Adding up the bond energies of all the bonds in the reactants

21
Q

How do you work out the amount of energy given out from bond making

A

Adding up the bond energies of all the bonds in all the products

22
Q

Give some facts on ammonia

A

It breaks down when it is heated

It’s a colourless gas

23
Q

What happens when ammonium chloride breaks down

A

It firms ammonia gas and hydrogen chloride gas

24
Q

What is a closed system

A

When I ether reactants nor products can enter or leave

25
Q

What is the position of equilibrium

A

When reversible reactions reach a balance point, where the amount of reactants and the amount of products formed remain constant

26
Q

When is an equilibrium reached

A

When the forward and reverse reactions occur at the exactly same rate

27
Q

What is le chateliers principle

To do with dynamic equilibrium

A

If a dynamic equilibrium is disturbed by changing the conditions, the reaction moves to conteract change

28
Q

How is a does concentration change the position of equilibrium

A

If more of a reactant is added, the system would work by removing this reactant and making more of the products

29
Q

How does temperature change the position of equilibrium

A

Decreasing the temp moves the position of E in the direction of the exothermic reaction

Increasing the temp moves the position of E in the endothermic direction

30
Q

How does changing the pressure effect the post Position of equilibrium

A

Increasing the pressure moves the position of E to the suede with the least number of molecules

31
Q

What happens if you add a catalyst to an equilibrium reaction

A

It reduces the time to reach equilibrium but doesn’t change the position of E

32
Q

Why do particles need to smash into one another

A

So the bonds are broken and new substance is made

33
Q

What happens if activation energy is low

A

Particles don’t need to collide with much energy to react

Meaning they’ll react as soon as they’re mixed

34
Q

What does carbon dioxide produce during a reaction

A

Fizzing

35
Q

What’s is the concentration

A

Amount of molecules dissolved in a volume of water

36
Q

What can’t you do if two reactants are gases

And what the alternative thing to do

A

Increase the concentration

So you increase the pressure

37
Q

How can the rate of reaction between marble chips and hydrochloride acid be changed

A

Changing the temperature and surface area of reactants

38
Q

Why are powders like icing sugar flour and custard powder dangerous

A

They react very quickly as they have very large surface areas so they need to avoid naked flames

39
Q

What are the pros of catalysts

A

Very small amounts can be used and they can be used again and again thus many industrial chemical reactions use them

40
Q

What is a drawback if catalysts

A

They are very specific to what they can be used on

41
Q

What are catalysts in living things called

A

Enzymes

Sometimes known as biological catalysts

42
Q

Where do reactions stop

A

One or both of the reactants are used up

43
Q

What is the reactant called that causes the reactions to stop

A

Limiting reactant

44
Q

How to measure the rate of reaction on a graph on a fine point on the graph

A

Make a tangent (straight line) on the curve of where the point asked is
Then draw a right angles triangle and find the steepness of the tangent by dividing the height by the width
Thus = vol. gas collected (divided) time taken

45
Q

To measure reactions rates what do you need to do

A

Observe the reaction at time intervals
see amount of gas released
Change in mass
The colour or appearance change

Chemistry Rate Of Reactions (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions