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Chemisty > Mod 7 > Flashcards

Mod 7 Flashcards

1
Q

What are the physical properties? (5of them)

A
  • Boiling point
  • Melting point
  • Density
  • Conductivity
  • Solubility
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2
Q

What are the chemical properties? (2 of them)

A
  • Stability
  • Reactivity
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3
Q

what is the polarity of Alkanes?

A

They are slightly polar but due to geometry they cancel out this polarity and become NON-POLAR.

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4
Q

What range of carbon chain of alkanes is it a solid liquid or gas?

A

C1 <–> C4 : Gases
C5 <–>C18: Liquid
Higher than C20 : waxy solid

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5
Q

What is the solubility of Alkanes?

A

They are insoluble in water due to the polarity being non polar while water is polar and like dissolves like and these 2 are not like substance and Alkanes are not able to form hydrogen bonds with water.

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6
Q

How does the temporally dipole- dipole forces happen?

A

In larger molecules there are more electrons, and more chances of unequal electron sharing resulting in an oscillation effect hence a temporarily dipole- dipole forming. Thus, increasing the overall strength of the dispersion force

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7
Q

What intermolecular forces are present in Alkanes?

A

Dispersion and temporally dipole- dipole forces.

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8
Q

What is the conductivity of Alkanes?

A

They are poor conductors as they don’t have any free-flowing electrons, as they are held tight.

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9
Q

What is the stability and a reactivity of Alkanes(Chemical properties)?

A

Relatively stable and unreactive

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10
Q

What is the boiling and melting point of Alkenes and Alkynes?

A

Relatively low since low energy is required to overcome the weak dispersion force.

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11
Q

What is the density of Alkenes and Alkynes?

A

Low density

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12
Q

What is the solubility of Alkenes and Alkynes?

A

Insoluble in water, as________

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13
Q

What is the conductivity of Alkenes and Alkynes?

A

Poor conductors

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14
Q

OUT of Alkenes, alkanes and alkynes what is saturated and unsaturated?

A

Alkanes are saturated.
Alkenes and Alkynes are unsaturated

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15
Q

What bond is present in a single bond?

A

Stigma bond

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16
Q

What bond is present in a double bond?

A

Pi bond and Stigma Bond

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17
Q

What is the strong bond pie bond or sigma bond?

A

Stigma bond

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18
Q

What reaction takes place when Cl2 and Br2 and in the presence of what catalyst, in a alkane?

A

Substitution reaction takes place in the presence of UV light (catalyst)

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19
Q

What is the catalyst in Hydration and the thing reacting with the alkenes?

A

Alkene reacts with water, and the catalyst is Dilute sulfuric acid.

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20
Q

What happens when a reaction takes place with Alkenes?

A

The alkenes have double bond and the pi bond breaks allowing for 2 new bonding sites to form.

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21
Q

What is the catalyst in hydrogenation and the thing reacting with the alkenes?

A

Alkenes reacts with H2 catalyst is Pt- platinum.

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22
Q

What are the different types of reaction that alkenes undergo?
(5 of them)

A
  • Hydrogenation
  • Halogenation
  • Hydrohalogenation
  • Hydration
  • Dehydration
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23
Q

What is the halogenation thing reacting with the alkenes?

A

Reacts with a halogen (group 17) typically Cl2 and Br2

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24
Q

hydrohalogenation and the thing reacting with the alkenes?

A

Alkene reacts with hydrogen halide

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25
Q

What is the catalyst in Dehydration and the thing reacting with the alkenes?

A

So, the Alkane is put into the presence of a concentrated sulfuric acid catalyst to form an alkane and water.

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26
Q

What is the Linder’s Catalyst?

A

It is a poisoned Platinum catalyst. When the alkyne undergoes a reaction, it prevents the formation of an alkane and stops the alkene from further reaction.

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27
Q

What is the term Hydrogen hangs with his homes used?

A

When hydrohalogenation (H-Br) occurs, The hydrogen from the halogen haled dissociated and the hydrogen goes to the carbon with the more hydrogens on that once carbon, while the halogen goes to the other bonding site.

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28
Q

what is Markovnikov’s rule in alkenes?

A

When an unsymmetrical alkene is reacted with hydrogen halide (H-Cl), the hydrogen from the hydrogen halide adds to the doubly bonded carbon atom, which has the greater amount of hydrogens already attached to it.

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29
Q

What is the Bromine water test?

A

Is a chemical analysis technique used to identify the presence of unsaturation in organic compounds.

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30
Q

What happens when alkanes react with bromine water?

A

They do not react with the bromine water and the dark yellow colour remains unchanged.

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31
Q

What happens when alkenes react with bromine water?

A

They do react with the bromine water and the Br(aq) decolourises to colourless.

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32
Q

What are fossil fuels?

A

Energy rich compounds formed by geological actions.

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33
Q

What are the 3 major types of fossil fuels?

A

Coal (pure carbon)
Natural gas
Crude oil/ petroleum

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34
Q

What is crude oil and how is it formed?

A

They are complex mixtures of hydrocarbons usually formed from decaying marine organisms,

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35
Q

What are the positive implications of using hydrocarbons (2 of them)?

A

Positive economical development,
They are used in
-Cooking
-Automobile fuels

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36
Q

What are the negative environmental implications of using hydrocarbons (4 of them)?

A

Co2
Co and soot (incomplete combustion)
Polymer production
Oil spills

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37
Q

What are the negative implications of co2 of hydrocarbons on the environment?

A

Co2 is produced from complete combustion; it can contribute to the enhanced greenhouse effect which causes rise in global temperatures, causing ice caps to melt, which increases sea levels.

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38
Q

How do we minimise Co2 on environmental inputs?

A

Use post combustion capture techniques.

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39
Q

How to prevent incomplete combustion,affecting the environment(2)?

A

Use a catalytic converter
Use a high air:fuel ratio

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40
Q

What is the negative implication of soot and CO (incomplete combustion) on the environment?

A

Co and soot are formed when there is insufficient amount of oxygen, they reduce the air quality as co is toxic as it binds to haemoglobin reducing the amount of oxygen carried by blood and soot is carcinogenic.

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41
Q

How to answer questions on environmental implications of hydrocarbons?

A

Give example of some hydrocarbon (octane and ethanol
Discuss the environmental impact
Include chemical equation

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41
Q

What is the negative implication of polymer pollution on the environment?

A

Polymers derived from hydrocarbons are not biodegradable, so they are not readily broken down by bacteria, which increases landfill , contributing to the death of marine organisms .

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42
Q

What is the negative implication of oil spills on the environment?

A

When extracting and transporting crude oils,it can lead to oil spills, which causes marine organism and plant life, which poses a negative impact on the economy as jobs and tourism industry can be lost.

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43
Q

What is the functional group of Alcohols?

A

Hydroxyl functional group (-OH)

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44
Q

What is the formula for Alcohols?

A

CnH2n+1 OH

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45
Q

What is primary alcohol?

A

Is only contains one carbon atom which is bonded to the carbon atom containing the -OH group

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46
Q

What is secondary Alcohol?

A

The carbon atoms which contain the OH Group are surrounded by 2 carbon atoms.

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47
Q

What is Tertiary Alcohol?

A

The carbon atoms which contain the OH groups are surrounded by 3 carbon atoms.

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48
Q

What is the polarity of alcohol?

A

They are polar

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49
Q

Why primary alcohols have the highest BP?

A

Due to the position of the hydroxyl group being at the ends it has the ability to form strong hydrogen bonds while secondary Alcohol and tertiary are blocked by neighbouring carbon atoms thus making it harder for hydrogen bonds to occur. Thus boiling points of primary alcohols are higher.

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50
Q

What is the solubility of alcohol?

A

Due to the polar nature they are able to form strong hydrogen bond, with the polar water

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51
Q

How are alkanols amphipothic?

A

They have a polar hydroxyl end, which ss hydrophilic and a nonpolar tail, which is hydrophobic, the polar end of the alcohols is soluble in water and able to dissolve substance via dipole dipole, ion dipole or hydrogen bond, while he non polar end is able to dissolve non polar substances with dispersion forces.

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52
Q

What happens to the water solubility of Alcohols as the non-polar hydrocarbon chain increases?

A

It becomes less soluble as the non polar alkyl group dominates and the polar hydroxyl group is insignificant, thus the hydrocarbon chain outweighs the effect of he polar Hydroxyl group

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53
Q

How are alcohols produced through hydration?

A

Through the hydration of Alkenes with the presence of dilute sulfuric acid , as the double bond breaks down, allowing 2 new bonding sites to form, and the water molecule breaks down into its components (H and OH). and the h goes to the side with more hydrogen while the Oh goes to the other site and another alcohol can also form (minor)

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54
Q

What are the 5 controlled condition fermentation needs?

A

Suitable grain or fruit mashed with water
Alcohol tolerant yeast, so that the yeast wouldn’t die
Anaerobic condition, to prevent cellular respiration (produces co2 and h20)
Temp around 37 degrees. Speed up the reaction and prevent yeast from denaturing.
Low PH (Acidic) to prevent C2 H5 OH being Oxidised to CH3 COOH by complex side reaction

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55
Q

What is the fermentation of Alcohol?

A

Where a renewable source (sugar cane) are converted to ethanol and CO2, by a yeast enzyme (biological enzyme)

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56
Q

What is the formula of ethanol undergoing combustion?

A

C2H5OH(l) + 3O2(g) —> 2CO2(g) +3H2O (l)

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57
Q

How to achieve higher ethanol levels?

A

add more alcohol

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58
Q

What is the procedure for fermetation of alcohols?

A
  1. Weight 15g glucose into 500ml conical flask
    2.Add 150ml warm water and shake
    3.Add 5 of yeast
    Seal with stopper
    4.Weigh the fermentation assembly and reweigh at regular intervals, until constant mass is achieved
    5.Find the CO2 releases by initial -final. Then use molar ratio to find ethanol
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59
Q

What do we use to quantify the energy released upon combustion? (2 equations)

A

qw=mCAt → calorimetry
AH= q(fuel)/n(fuel)

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60
Q

What do we assume in calorimetry?

A

Heat released by fuel = heat absorbed by water

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61
Q

What is the molar heat of combustion?

A

The heat energy released by fuel when one mole of a substance undergoes complete combustion.

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62
Q

What is the main aim of Heat of combustion (Alcohols)?

A

To determine and compare heats of combustion of different alcohols

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63
Q

What is the method of heat of combustion(Alcohols)? (6)

A
  1. Weigh and empty aluminium can fill about 100ml of water then reweigh (find the mass of water)
    2.Measure initial water temp
    3.Weigh spirt burner
    4.Assemble apparatus, light the burner
    5.Heat for 10 min record final water temp
    6.Extinguish reweigh spirit burner
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64
Q

What happens to the energy when you break bonds?

A

Energy is absorbed

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65
Q

What happens to the energy when you form bonds?

A

Energy is released

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66
Q

What is the risk assessment of heat of combustion? (2)

A

-Incomplete combustion (when there is a small distance between the flame and can) → not enough oxygen, can cause a toxic gas CO well filtered
-Alcohols are extremely flammable → use a spirt burner

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67
Q

What are some improvements of the Heat of combustion (Alcohols)? (3)

A

Use a heat resistant shield
Use a lid
Reduce the distance between the can and the flame and but make sure it is not too close do that incomplete combustion does not occur,

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68
Q

What is the trend when there is an increased number of Alkanol carbon chains?

A

When longer Alcohols are combusted more bonds need to be formed in the product which cause more energy to be released.

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69
Q

How do we convert from KJ/mol to KJ/g?

A

Divide by molar mass

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70
Q

How do we convert from KJ/g to KJ/mol?

A

Multiple by molar mass

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71
Q

Is Ethanol are renewable biofuel (what are the 3 formulas)?

A

Yes it is derived from living matter (greenhouse neutral)
What are the 3 equations which make ethanol greenhouse neutral?
INPUT: 6CO2 +6H2O → C6H12O6 + 6O2
OUTPUT: C6H12O6 —(yeat)–> C2H5OH +2CO2
2C2H5OH +6o2 → 4CO2 + 6H20

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72
Q

Steps of fermentation and combustion of ethanol? (6)

A

1.Sunlight and co2 and H2O and energy for fertiliser and cultivation, for the production of sugarcane.
2.The photosynthesis occurs to produce glucose which is then converted into sucrose and starch
3.Then industrial processing occurs making aqueous ethanol
4.then fractional distillation occur to make pure ethanol
5.Then put into cars so combustion can occur causing releases CO2 and H2O

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73
Q

What Are the Disadvantages of Using ethanol? (4)

A
  • Requires large area of fertile land
    -Potential land degradation problems such as soil erosion make soil unstable, harder for tree to grow
    -Fertilizer runoff can occur into waterways causing algae blooms to occur, this is where the algae expands which takes up most of the water and less sunlight would enter less plant and coral would grow which would affect the food chain as secondary and primary producers are not able to hide from predators. And it take up all the oxygen in the waterways so that animals in the seas are not able to have oxygen
  • More expensive car modifications
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74
Q

What are the advantages of using ethanol? (4)

A

-Produces less co2 overall relative to petrol, less greenhouse gases
Equation:
Ethanol: C2H5OH + 3O2 → 2CO2 +3H2O
Octane (petrol): C8H18 +25/2 O2 → 8CO2 +9H20
-Less pollutants such as soot and CO
-More likely to undergo combustion
-Increase Octane rating of fuel (knocking)

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75
Q

what is knocking?

A

Is premature combustion or random combustion

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76
Q

What does ethanol do to the knocking effect?

A

It reduces the knocking effect, thus it boast octane rating is engine resistant to knocking

77
Q

What are aldehydes function group?

A

Carbonyl C=O which is bonded to an H atom at the end

78
Q

What is the sufix of aldehydes?

A

-al

79
Q

What are the function group of ketones?

A

Contain a carbonyl (C=O) function group bonded to 2 carbon atoms

80
Q

What is the suffix of ketones?

A

-one

81
Q

What Are the intermolecular forces of aldehydes?

A

Dispersion
Dipole dipole

82
Q

What is the polarity of ketones and aldehydes?

A

Polar

83
Q

What is the solubility of Aldehydes?

A

Smaller aldehydes are soluble since they form strong hydrogen bonds with water

84
Q

What are the reactions that alcohol can undergo?
(4)

A

Combustion
Dehydration
Substitution
Oxidisation

85
Q

What is the combustion reaction with alcohol?

A

Where and alcohol undergoes a reaction with oxygen to produce co2 and h20

86
Q

What is dehydration of an alcohol and what is its catalyst?

A

Where an alcohol turns into a alkene and water (which is take out), which the catalyst being conc. H2SO4

87
Q

What is Zaitsev’s rule?

A

When dehydration occurs in more than one product, the major product is more saturated alkene, so there are less hydrogens on the double bond than the minor.

88
Q

What is substitution of an alcohol?

A

When a hydrogen halide undergoes a reaction with alcohol, it forms a haloalkane and water.

89
Q

What is the oxidation of alcohol?

A

Alcohols can be oxidised by strong oxidants with heating. Strong oxidants such as Acidified MnO4- Cr2O72-

90
Q

What happens when a primary alcohol is oxidised?

A

Alcohols can oxidise to form aldehydes and carboxylic acid

91
Q

What happens when a secondary alcohol is oxidized?

A

Are oxidized to ketone

92
Q

What is the function group of carboxylic acid?

A

R- COOH

93
Q

What is the suffix of carboxylic acid?

A

-oic acid

94
Q

Why are carboxylic acids stronger than Alcohols?

A

Carboxylic acid have an additional polar carbonyl (C=O) dorm a dimer group, so they are capable of forming extensive hydrogen bonds.

95
Q

What is the solubility with carboxylic acid?

A

Smaller carboxylic acids are water soluble, since they are able to form strong hydrogen with water

96
Q

How are esters formed?

A

Carboxylic acid + Alcohol <–> Ester + water
The Oh from the carboxylic acid and the H atom from the alcohol and make water.

97
Q

What is the function group of esters?

A

-COO

98
Q

How are esters named?

A

1- the first put the number of C of the Alcohol and then add -yl
2- then put the number of carbon with the (an), then add -ote

99
Q

Compare the MP and the BP of carboxylic acid and esters?

A

Esters are not able to form H bonds as they are no O-H bonds, so they are easier bonds to break. Thus less energy is required to break resulting in a lower BP and MP.

100
Q

What is the aim of the esterification via reflux experiment?

A

To prepare and ester using reflux

101
Q

Why do we add(excess) 20ml of glacial acetic acid?

A

We add excess to that equilibrium shifts right increasing the yield

102
Q

What is the method for the esterification via reflux experiment?

A

1- mix 6 ml absolute ethanol and 20 ml Glacial acetic acid in a distillation flask
2- Add 10 drops of 18M H2SO4
3- clamp the flask and imerese in a 500ml beaker of water
4- add ceramic boiling chips
5- attach a reflux condenser
6- heat for 20 min

103
Q

What is refluxing?

A

Heating mixture in a flask with a cooling condenser

104
Q

What does refluxing (cooling condenser) do? (2)

A

Prevents the loss of volatile reactants and products as the vapour runs back into the flak
Allow high temps to be used

105
Q

Why do cooling condensers goes backwards?

A

When water goes against gravity to maximise time under contact with the flask to increase efficiency

106
Q

What are some hazards of esterification?

A

Indirect source of heat, safer for flammable substances
Using boiling chips to prevent overheating

107
Q

Why does esterification require conc. H2SO4 catalyst?
(2)

A

Speeds up the reaction by providing an alternate reaction pathway( lowering activation energy)
As a dehydrating agent so it absorbs water increasing the yield of the ester

108
Q

How are esters separated from reactants?

A

Fractional distillation
Separating funnel

109
Q

What is the odor of esters?

A

Fruity odour

110
Q

Where are esters used in?

A

Perfumes
Artificial flavors

111
Q

What is saponification?

A

Is the reverse of esterification
It is the hydrolysis of an ester, in a basic (ph>7) condition which produces alcohol and carboxylic acid which is the soap.

112
Q

What are fatty acids?

A

Are carboxylic acid with long unbranched chains

113
Q

What is glycerol?

A

It is an alcohol which forms the backbone of oils and fats

114
Q

What Are the 2 equations on forming soap(give the net equation)?

A

Triglycerides (ester) +3 water <—–> glycerol (alcohol) + 3 fatty acids (carboxylic acid)
3 fatty acid +NaOH (basic conditions) → 3 sodium carboxylate(SOAP) +3water
NET: Triglycerides +3NaOH <—-> glycerol + 3 soap

115
Q

What does the soap molecule look like?

A

Consists of a long hydrocarbon chain and a negatively charged Coo- head
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/=O__O-
(NON POLAR TAIL) (polar head)

116
Q

What does the nonpolar tail and the polar head attract?

A

NON polar hydrophobic tail attracts to greasy oils
Polar hydrophilic head attracts to water molecules via H- bonds

117
Q

How do micelles form (Saponification)?

A

1- soaps/ detergents dissolve in water
2- soap starts to lift of the oil with agitation as the polar tail attaches to the oil
3- oil particle completely “stabilised”

118
Q

Why do Micelles repel each other?

A

As the polar head are negatively charged the 2 negative heads of the micelles repel each other

119
Q

What is Emulation?

A

dispersion of small drops of one liquid (oil) throughout another liquid (water)

120
Q

What does emulation require to stabilise them?

A

Emulsifier

121
Q

How does soap act as an emulsifier?

A

As it forms a bridge between oily particles and water

122
Q

What is the problem with soap?

A

The concentrated mineral ions such as ca2+ and Mg2+ , which are present in hard water, can readily precipitate with soap to form scum which reduces the cleaning efficiency of soap.

123
Q

What is the structure of detergents?

A

Polar changed hydrophilic tail
Non polar hydrophobic head

124
Q

Why do we use detergents instead of soap?

A

Detergents don’t form precipitates with hard water containing ca2+ and mg2+ cations, thus detergents are more effective cleaning agent in hard water

125
Q

What is biodiesel?(2)

A
  • esters
  • renewable fuel
126
Q

Where are biodiesel sourced?

A

Transesterification of water oils and fats

127
Q

What is transesterification?

A

Involves triglyceride undergoing a reaction with methanol,

128
Q

What is the function group of amines?

A

NH2

129
Q

Suffix of amines?

A

-amine

130
Q

What are primary amines?

A

The function group is surrounded by one c

131
Q

What are secondary amines?

A

The function group is surrounded by 2 C

132
Q

What are tertiary amines?

A

The function group is surrounded by 3 C

133
Q

What is the function group of amides?

A

– C – N–
|| |
0

134
Q

How are amides produced?

A

Carboxylic acid + amine <-A(deta)-> Amide + water

135
Q

What does the delta mean?

A

Represents high temps

136
Q

What is the suffix of amides?

A

– amides

137
Q

What is the strength of the hydrogen bond in primary secondary and tertiary amines?

A

The NH group in a primary amine is very exposed but in a secondary it is not as exposed, as it is surrounding 2 neighbouring carbon atoms , while in tertiary there is no NH group.

138
Q

What forms stronger hydrogen bonds OH or NH?

A

O is more electronegative than N thus the electronegativity difference between is greater in O-H than N-H and thus O-H is able to form stronger hydrogen bonds

139
Q

What is the polarity of amines/amides?

A

Polar

140
Q

Do alcohols have a higher BP or Amines?

A

Alcohols as they have a strong OH group thus able to form stronger H Bonding that NH.

141
Q

Why are amides stronger bonds than amines of similar mass?

A

Amides contain an additional polar C=O group which is capable of forming extensive H bonding, they also form an extensive H bonded network, thus resulting in a higher Bp.

142
Q

Are amines and amides soluble in water?

A

Yes small amines and amides are soluble in water, as they are able to form strong H bonds with water.

143
Q

What are amines considered a weak base?

A

As they can accept H+ ions from a bronsted lowry acid, to form a protonated amine.

144
Q

What is the boiling point of the substance we learnt? (6), highest to lowest

A

Amides
Carboxylic acid
Alcohols
Amines
Aldehydes
Hydrocarbons (alkenes, alkane…)

145
Q

What are structural isomers?

A

Compounds with the same molecular formula but different structural formula

146
Q

What are the 3 structural isomers?

A

1- chain isomers
2- position isomers
3- functional group isomers

147
Q

What are chain isomers?

A

same molecular formula but different structural formula, due to the rearranged of the carbon skeleton

148
Q

What are Position isomers?

A

same molecular formula but different structural formula, due to the function group/ substitute changing positions

149
Q

What are functional group isomers?

A

same molecular formula but different structural formula, due to the different function group

150
Q

How can isomers have different Bp based on their shapes?

A

Isomers with more branched out cannot pack as closely as straight chained isomers, which can lead to weaker dispersion forces and lower Bps

151
Q

What are polymers?

A

High molecular weight molecules form from simple repeating monomers

152
Q

What is the process of producing polymers?

A

Polymerisation

153
Q

What are the 2 ways polymers are formed?

A

Addition–> produces nor by product
Condensation –> produces a by product

154
Q

What are the additional polymerases?

A

Polymers formed by chemically joining many monomers together without any by product, as the double bond breaks and allows addition of more monomers.

155
Q

Why do we use alkenes to make additional polymers?

A

Alkenes has a strong sigma bond and a weak pi bond which causes alkenes to be widely reactive as it is able to make many products

156
Q

What are the 4 type of addition polymers?

A

Polyethene
Polychloroethene
Polystyrene
polytetrafluoroethylene

157
Q

What is the monomer for polyethene?

A

Ethene

158
Q

What Are the 2 major forms of polyethene

A

High density polyethene (HDPE)
Low density polyethene (LDPE)

159
Q

What Are the features of High density polyethene (HDPE)?

A

-Very low molecular distance (very dense)
-Insignificant branching (linear chain structure)
-Stronger dispersion forces as they are very tightly packed together, —high degree of crystalline
-Strong and ridge
-Higher BP and MP

160
Q

What Are the features of low density polyethene (LDPE)?

A

-Very high molecular distance (non linear chains )
-Significant branching (less dense)
-Weaker dispersion forces, as are not as tightly packed,
-lower degree of crystalline
-Soft and flexible
-Lower BP and MP

161
Q
A
162
Q

What is the monomer for Polychloroethene, used for?
(2)

A

Large polar CL substitute, restricts the movement of the polymer
The CL- C creates an electronegativity difference, causing dipole dipole forces to occur, increase the attraction, and making the polymer less flexible.

163
Q

What is the monomer of Polystyrene?

A

Styrene

164
Q

What is the substitute of Polystyrene called?

A

C6H6 Benzene

165
Q

What are the features of polystyrene?

A

Bulky benzene substitutes
Stronger dispersion focus, causes more attraction
Very hard and ridge

166
Q

What are the 3 additives used in addition polymers?

A

-Stabilisers
-Plasticizers
-Blowing gas into Polystyrene, to make styrofoam

167
Q

What do we do if the C-Cl is vulnerable to Uv attack in polychloroethene?

A

Use UV stabilisers to prevent UV decomposition

168
Q

Why do we use plasticisers in polychloroethene?

A

To softener the polymer so that garden hoes are made

169
Q

What is (PTFE) polytetrafluoroethylene monomer?

A

Tetrafluoroethene

170
Q

What are (PTFE) polytetrafluoroethylene properties?

A

Contains large substitutes
The F is the most electronegative, so the electrons are very closely to the nucleus of the F and thus resulting in no electron movement and no chances of dispersion forces occurring, with other substances

171
Q

What are the 4 properties of polymers?

A

Average chain length
Chain branching
Subsitutents
addities

172
Q

What is the Higher BP High density polyethene (HDPE) or Low density polyethene (LDPE)?

A

HDPE as it has stronger dispersion forces, higher BP and MP

173
Q

What happens when the chain length increases in polymers?

A

Longer polymers are higher molecular weight and higher MP and stronger

174
Q

What happens when the chain branching increases?

A

Results in a less orderly packed lower density less crystalline degree more flexible as it has weaker dispersion forces.

175
Q

What does the substitute do in polymers?

A

Having heavy substitutes restrict the movement of the molecules

176
Q

What are condensation polymers?

A

Formed when monomers chemically combine by eliminating a small molecule (h2O)

177
Q

What are the 2 condensation polymers?

A

Polyester
Polyamide

178
Q

What are polyesters?

A

They are condensation polymers in which the monomers are joined by an ester (-COO-) link

179
Q

How are polyesters formed?

A

By combining monomer with a carbonyl (-COOH-) group and a hydroxyl (-OH-) group

180
Q

What is PET?

A

Polyethylene terephthalate, type of polyester

181
Q

What are the strongest intermolecular force polyesters?

A

Strong dipole dipole attraction as they have a repeating polar ester group no OH group.

182
Q

What are the uses of polyesters?

A

Drinking bottles and food packaging

183
Q

What are polyamides?

A

Condensation polymers, in which the monomers are joined by an amide (-CONH-) link

184
Q

Condensation polymers, in which the monomers are joined by an amide (-CONH-) link

A

Formed by combing a carboxyl (-COOH) and a amino (-NH2) group

185
Q

What is Nylon- 6,6?

A

It is a type of polyamide

186
Q

What are the monomers of nylon-6,6?

A

Adipic acid (carboxylic acid) and hexamethylenediamine (amide)

187
Q

What is the strongest intermolecular force of polyamides?

A

Hydrogen bonding as they have a repeating polar amide group (NH)

188
Q

What is the use of polyamides?

A

Fishing lines and ropes

189
Q

Are condensation polymers permeable in water?

A

Yes as they dont let water pass through.

Chemisty (2 decks)

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