Chemical Reactions Flashcards

1
Q

Requirements for reactions to occur (2)

A

must have correct collision geometry

must collide with sufficient energy

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

What happens to rate of reaction over time (2)

A

slows down until stops

time progresses –> concentration of reactant decreases –> decreases frequency of reaction

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

How can rate of a reaction be measured

A

how quickly reactant is used

how quickly product formed

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

How can rate of reactions that produce a gas be measured (2)

A

rate of loss in mass of reactants (mass balance)

rate of gas formation (gas syringe + displacement of water)

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

Gas Syringe rate of reaction diagram requirements (3)

A

syringe should have graduation marks

delivery tube must not be cut off

plunger should be slightly pushed out

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

Limitations of using a gas syringe to measure rate of reaction (3)

A

bung may not be securely fit –> gas might escape

delivery tube may not be securely fit –> gas might escape

if plunger is stiff –> gas pressure will increase

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

Displacement of water rate of reaction experiment requirements (3)

A

gases produced must be insoluble under water

graduation marks on measuring cylinder

delivery tube should not be cut off

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

Limitations of using displacement of water to measure rate of reaction (3)

A

bung may not be securely fit –> gases might escape

delivery tube may not be securely fit –> gas might escape

if gas is soluble in water not all gas is collected

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

Calculating the rate of reaction

A

measuring change in quantity over time interval

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

Factors that effect rate of reaction (4)

A

Concentration of reactants

Temperature

Particle Size/Surface Area

Catalyst

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

How concentration increases the rate of a reaction (2)

A

increased concentrations –> more particles to collide together + react

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

Relationship between concentration and rate of reaction

A

directly proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How temperature increases rate of a reaction (3)

A

increased temperature –> particles have more energy + move around faster –> greater chance of collisions + reaction happens quicker

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

How particle size/surface area increases rate of a reaction (2)

A

smaller particle size + greater surface area –> reaction surface area increased + more surface for collisions

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

Reducing particle size to increase rate of reaction in industry

A

catalytic converters - have honeycomb structure which increases surface area

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

Dangers of reduced particle size causing increased reaction rate in industry

A

coal dust - rate of combustion fast as they have large surface area (explosion)

17
Q

How catalysts increase rate of a reaction

A

lower activation energy needed for reaction

18
Q

Example of catalyst to speed up a reaction (2)

A

adding manganese (IV) oxide to hydrogen peroxide increases speed of it decomposing

2H2O2 (aq) –> 2H2O + O2 (g)

19
Q

Ion-electron equation for reduction of element

A

element + (valency)e^- –> ion

20
Q

Ion-electron equation for oxidation of element

A

element –> Ion + (valency)e^-

21
Q

Define redox reactions

A

when oxidation and reduction reactions happen at the same time

22
Q

Calculating overall redox reactions (4)

A

combine individual oxidation + reduction reaction

electrons must be equal to cancel out

reactants of redox reaction is left side of oxidation and reduction reaction

products of redox reaction is right side of oxidation and reduction reaction

23
Q

Define oxidation in terms of oxygen

A

element gaining oxygen in a reaction

24
Q

Define reduction in terms of oxygen

A

element losing oxygen in reaction

25
Q

Define an oxidising agent (2)

A

substance which accepts electrons

is reduced (gains electrons)

26
Q

Define a reducing agent (2)

A

substance which donates electrons

is oxidised (loses electrons)

27
Q

Where are good/strong reducing agents found in the reactivity series

A

top of reactivity series since they easily lose electrons

28
Q

Where are good/strong oxidising agents found in reactivity series

A

bottom of reactivity series since they easily gain electrons

29
Q

Name common oxidising agents (permanganate) (3)

A

acidified potassium permanganate

MnO4^- –> Mn^2

changes from purple to colourless

30
Q

Name common oxidising agents (dichromate) (3)

A

acidified potassium dichromate

Cr2 O7^2- –> Cr^3+

used in breathalysers - determine alcohol content in breath by colour change from orange to green

31
Q

Name common reducing agents (2)

A

Sulfur dioxide

Carbon monoxide - extraction of iron in blast furnace

32
Q

Define oxidation state (2)

A

represents how many electrons an atom loses or gains to become an ion

written as math sign (+) then number