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Chemistry A Level Key Knowledge > Names And Conditions Of Mechanisms, And Key Definitions > Flashcards

Names And Conditions Of Mechanisms, And Key Definitions Flashcards

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1
Q

What is the name, reagent and conditions for the mechanism from Haloalkane to Alcohol?

A

Nucleophilic Substitution
Reagent: NaOH
Conditions: Aqueous, heat under reflux

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2
Q

What is the name, reagent and conditions for the mechanism going from Haloalkane to Amine?

A

Nucleophilic Substitution
Reagent: Excess NH3
Conditions: Ethanol, heat and pressure

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3
Q

What is the name, reagent and conditions for the mechanism going from Haloalkane to Nitrile

A

Nucleophilic Substitution
Reagent: KCN
Conditions: Water and ethanol

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4
Q

What is the name of the process, reagent and conditions to go from Nitrile to Amine?

A

Reduction
Reagent: H2 (in the equation; 2H2)
Condition: Nickel (Ni) catalyst

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5
Q

What is the name, catalyst and conditions for the mechanism going from Alcohol to Alkene?

A

Elimination/Dehydration
Catalyst: Hot concentrated H2SO4
Conditions: Hot

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6
Q

What is the name, reagent and conditions for the mechanism going from Alkene to Alcohol?

A

Direct Hydration
Reagent: H3PO4
Conditions: Steam

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7
Q

What is the name, reagent and conditions for the mechanism going from Haloalkane to Alkene?

A

Elimination
Reagent: KOH/NaOH (acts as base, not nucleophile)
Conditions: Ethanol, Reflux

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8
Q

What is the name, reagent and conditions for the mechanism going from Alkene to Haloalkane?

A

Electrophilic Addition
Reagent: HBr, HCl, Br2, Cl2
Conditions: No conditions required

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9
Q

What is the name and reagent for the mechanism going from Alkene to Alkyl Hydrogen Sulfate?

A

Electrophilic Addition

Reagent: H2SO4

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10
Q

What is the name of the process of going from Alkyl Hydrogen Sulfate to an Alcohol, and what is the reagent?

A

Hydrolysis

Reagent: H2O

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11
Q

What is the name, reagent and conditions for the process of going from Alkane to Haloalkane? And what are the names of the steps?

A 
Free Radical Substitution
Reagent: Either Br2 or Cl2
Condition: U.V light
Steps: 
Initiation
Propagation (two equations)
Termination
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12
Q

Define a Nucleophile

A

An electron pair donor

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13
Q

Define an Electrophile

A

An electron pair acceptor (AKA a reactive intermediate

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14
Q

Define a Base

A

A proton acceptor

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15
Q

Define an Acid

A

A proton donor

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16
Q

What is meant by “More Stable Carbocation”?

A

The major product has the more stable carbocation. It’s a positive carbon with more carbons around it. E.g a 1° carbocation is less stable than a 2° one.
This is due to the positive inductive effect.

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17
Q

Define the Positive Inductive Effect

A

The ability to release electron density through a covalent bond

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18
Q

What is the name, reagent and conditions for the mechanism for the Nitration of Benzene (Forms Nitrobenzene)? How is the electrophile/reactive intermediate formed?
How is the Catalyst Re-Formed?

A

Electrophilic Substitution
Reagent/Conditions: Conc HNO3 and Conc H2SO4 Catalyst
H2SO4 + HNO3 —> HSO4- + H2O + NO2+

HSO4- + H+ —> H2SO4

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19
Q

What is the name, reagent and conditions for the mechanism going from Benzene to Phenylethanone (Friedel-Crafts Acylation)
What is the equation for the formation of the electrophile/reactive intermediate
How is the catalyst Re-Formed?

A

Electrophilic Substitution
Conditions/Reagents: An acyl chloride e.g RCOCl and an AlCl3 catalyst

RCOCl + AlCl3 —> RCO+ + AlCl4-
(RCO+ = Electrophile)
AlCl4- + H+ —> AlCl3 + HCl

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20
Q

What occurs when forming an Amine from a Haloalkane, if the Haloalkane is also in Excess as well as the NH3?

A

Further Substitution
Product reacts with Haloalkane to form a 2° anime, and that product reacts to form 3° amine and then that product reacts to form a Quaternary (4°) Ammonium Salt (used in hair conditioner)

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21
Q

What are the Cons to forming an Amine from a Haloalkane for either nucleophilic substitution with excess NH3 (Route 1), or nucleophilic substitution with KCN to form Nitrile, and then reduction with 2H2 and Ni catalyst (Route 2)?

A

Route 1: Risks Further Substitution

Route 2: KCN is Toxic and also it requires two steps instead of one

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22
Q

What is the name of the process, reagent and conditions for turning the Nitro group (NO2) on Nitrobenzene to an Amine group (NH2)? Give a general equation for the transformation of the alkyl group.

A 
Reduction
Reagent: HCl
Condition: Tin (Sn) Catalyst
NO2 + 6[H] ---> NH2 + 2H2O
(NO2 and NH2 are attached to benzene)
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23
Q

What is the risk of reacting HCl with Nitrobenzene to change group to an amine group? And how is this solved?

A

Risk of product reacting with HCl to form Phenylammonium Chloride
(NH2 group becomes NH3+ with Cl- nearby like when amino acids are in acidic conditions)

Solution:
Add stronger base (NaOH)
NH3+ + Cl- + NaOH —> NH2 + NaCl + H2O
(NH2 and NH3+ are attached to benzene)

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24
Q

What is the name, reagent and conditions for the mechanism going from a Ketone to a 2° Alcohol or an Aldehyde to a 1° Alcohol?
(Reduction)

A

Nucleophilic Addition
Reagent: NaBH4
(For hydride ion nucleophile :H- )
Condition: Acidic Solvent Needed (For H+ in mechanism)

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25
Q

What is the name, reagent and conditions for the mechanism going from either a Ketone or Aldehyde to a 2° or 1° Hydroxy Nitrile group
(Reduction)

A

Nucleophilic Addition
Reagent: Potassium Cyanide, KCN, Aqueous and Ethanolic
(Nucleophile: -CN)
Conditions: Acidic Solvent Needed (For H+ in mechanism)

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26
Q

Give the name, conditions and reagent for the 1st method of making esters that you learnt.

A

Esterification (Reversible via hydrolysis)
Reagent: Carboxylic Acid + Alcohol
Conditions: Concentrated H2SO4 (H+) catalyst and Gentle Heat
(H2O is a side product)

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27
Q

What is Hydrolysis?

A

The breaking of covalent bonds using water

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28
Q

What are the two methods of Hydrolysis for splitting Esters? And what do both methods form?

A

Acid-Catalysed Hydrolysis
Reagent: Water
Conditions: Room Temp and Strong Acid Catalyst
Forms: Carboxylic acid and Alcohol

Base-Catalysed Hydrolysis
Reagent: Warm AQUEOUS NaOH
Forms: Salt of the acid (e.g Sodium Propanoate if using ‘something’ Propanoate) and Alcohol
(Once carboxylic acid forms, it reacts with NaOH in an acid base reaction)

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29
Q

What is meant by the term Unsaturated when applied to an Alkene?

A

Contains a C=C bond

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30
Q

Give the name, reagent and conditions for the mechanism used in the 2nd way if forming Esters you learnt

A

Addition-Elimination
Reagent: An Alcohol and an Acyl Chloride (RCOCl, all have names ending with ‘Oyl Chloride’)
No specified conditions

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31
Q

Give the name of the reagents for the 3rd way of forming an ester, more specifically, aspirin.

A

Salicylic Acid and Ethanoic Anhydride (Practical 10 on paper 2)

32
Q

For Industrial Use of Acylation Reactions, why is it more beneficial to use Acid Anhydrides (RCOOCOR’) over Acyl Chlorides (RCOCl)? 4 reasons

A
  • Cheaper
  • Less Corrosive
  • Doesn’t react with water to form a carboxylic acid
  • Safer as side product is Carboxylic acid and not HCl vapours
33
Q

Give the name and products for the mechanism when H2O is added to an Acyl Chloride (RCOCl)

A

Addition-Elimination

Products: Carboxylic acid and HCl vapours

34
Q

Give the name and products for the mechanism when ammonia (NH3) is added to an Acyl Chloride (RCOCl)

A

Addition-Elimination
Products: Amide (RCONH2) and NH4Cl
(Ammonium chloride salt)

35
Q

Give the name and products for the mechanism when an Amine is added to an Acyl Chloride (RCOCl)

A

Addition-Elimination

Products: N-Substituted Amide (RCONHR’) and an Ammonium Chloride Salt (RN(+)H3Cl)

36
Q

Why are Addition Polymers non-biodegradable? And how are they disposed instead?

A

C-C bonds in carbon chain are Non-Polar so cannot be attacked by nucleophiles therefore can’t be hydrolysed by H2O

They are incinerated or buried

37
Q

Why are Condensation Polymers biodegradable?

A

‘C’ in polar C-O can be attacked by nucleophiles so can be hydrolysed under acidic or basic conditions

38
Q

How is the condensation polymer ‘Polyester’ formed?

A

From a Dicarboxylic acid and Alcohol (Diol)

39
Q

How is the condensation polymer ‘Polyamide’ formed?

A

From a Dicarboxylic acid and Diamine

40
Q

What are the uses of Polyesters?

Terylene

A

Carpets, clothing, heat treated polyesters used in drink bottles

41
Q

What are the uses of Polyamides

A

Nylon 6,6: Fibres in clothing as it is elastic and has strong abrasion resistance
Kevlar: Body Amour and Crash Helmets as it is strong, light and heat resistant

42
Q

What are the reagent, condition and products for the Base Hydrolysis of Polyesters?

A

Reagent: H2O
Condition: NaOH
Products: Salt of Dicarboxylic acid, and Alcohol (Diol)

43
Q

What are the reagent, condition and products for the Acid Hydrolysis of Polyesters?

A

Reagent: H2O
Condition: H+
Products: Dicarboxylic Acid and Alcohol (Diol)

44
Q

What are the reagent, condition and products for Base Hydrolysis of Polyamides?

A

Reagent: H2O
Condition: NaOH
Products: Salt of Dicarboxylic Acid and Diamine

45
Q

What are the reagent, condition and products for Acid Hydrolysis of Polyamides?

A

Reagent: H2O
Condition: H+
Products: Diammonium Salt (NH3+) and Dicarboxylic Acid

46
Q

What is an amino acid? And subsequently what is an alpha amino acid

A

Made from a carboxylic acid and an amine, and and alpha amino acid has 1 carbon between them with an R group attached to it

47
Q

What happens to an amino acid at neutral pH?

A

Zwitterions form

+NH3 and COO-

48
Q

Key Facts About Zwitterions (3)

A

Form a solid lattice of Zwitterions
(Strong Electrostatic Forces Of Attraction Between COO- and +NH3)

Soluble as H2O can bond with COO- and +NH3

Mostly found as Solid or (aq)

49
Q

What happens to an Amino Acid in Acidic Conditions? (HCl)

A

Amino acid gets protonated:
NH2 group becomes Cl- +NH3
And also R group gets protonated if it also contains an amine group

50
Q

What happens to an Amino Acid in Alkaline conditions? (NaOH)

A

Amino acid gets Deprotonated:
COOH becomes COO- Na+ H2O

R group also gets Deprotonated if it contains a COOH group

51
Q

What is a peptide?

A

When amino acids join to form a chain (connected by a peptide bond/amide link) (O=C-N-H)

52
Q

If two amino acids are in a chain it is a…

A

Dipeptide

53
Q

If three amino acids are in a chain it is a…

A

Tripeptide

54
Q

What are the conditions for the hydrolysis (splitting) of peptides?

A

Boil (24 hrs)

6moldm-3 HCl catalyst

55
Q

What is the primary (1°) structure of a protein?

A

A sequence of amino acids (with the order and structure of these acids being crucial to the structure and function of the protein)
E.g. Glycine-Alanine-Valine-Leucine

56
Q

What is the secondary (2°) structure of a protein? And how is it held together?

A

Alpha-Helix or Beta-Pleated Sheet

Delta +ve hydrogen on N-H in amide link on one peptide chain forms a hydrogen bond with lone e- pair on C=O on amide link on another peptide chain
(R group may also form hydrogen bonds)

57
Q

What is the tertiary (3°) structure of a protein?

A

Alpha-Helix/ Beta-Pleated Sheet folds into a 3D shape

58
Q

How is the Tertiary (3°) structure of a protein held in place?

A

-Hydrogen bonding
-Some Ionic interactions
-Disulfite bonds (S-S) if two cysteine amino acids
(Covalent bond so stronger than H- Bond and has greater affect on structure)

59
Q

Key Enzyme Facts (3)

A
  • Catalyse just one type of reaction
  • Active Site is where the reaction takes place
  • It is “Stereospecific” and fits only one type of optical isomer
60
Q

What is the name of the reaction for producing Ethanol from Glucose? And what is the equation for it?

A

Fermentation/Anaerobic Respiration

C6H12O6(aq) —> 2CH3CH2OH(aq) + 2CO2(g)

61
Q

What are the conditions for fermentation?

A

Yeast, 35°C and NO oxygen

62
Q

Advantages of the Hydration of Ethene to form Ethanol?

A
  • Large scale production method
  • High purity product made
  • Readily available raw material
  • High reaction rate
  • Continuous Production Method
63
Q

Disadvantages of the Hydration of Ethene to form Ethanol

A
  • High temperature and pressure required so higher cost
  • Expensive/High cost equipment required
  • Crude oil is non renewable
64
Q

Advantages of Fermentation to form Ethanol

A
  • Uses renewable resources
  • Low tech method, so suitable for developing countries
  • Readily available and renewable materials
  • Low cost
65
Q

Disadvantages of Fermentation to form Ethanol

A
  • Slow rate of reaction
  • Impure Ethanol made needs distilling
  • Causes food prices to rise if crops are used to make ethanol instead of food
  • Batch production method is less effective
66
Q

Name N-Substituted Amide CH3CONHCH3

A

N-methylethanamide

67
Q

What is used as a reference standard in CNMR and HNMR spectroscopy? And what does it do?

A

TMS, aka tetra methyl saline.

Creates sharp peak at 0ppm.

68
Q

Why do we use TMS apart from due to its sharp peak?

A

It is unreactive
It is highly volatile (can be removed by evaporation easily)
Peak is always to right of spectrum

69
Q

Recrystallization steps for formation of Aspirin from Salicylic acid and Ethanoic anhydride (6 marks)

A

-Weigh mass of aspirin produced and add a minimum amount of hot solvent to form a highly concentrated saturated solution.
(Minimum amount maximises the yield of crystals at the end)
- Filter it Hot to remove insoluble impurities
-Cool it back down to get insoluble crystals to form
- Filter under reduced pressure and wash with cold solvent to remove soluble impurities
-Dry the sample

70
Q

Hydrogen based fuels create pollutants when combusted such as S(s) and N2(g). How do these react with oxygen at high temp? (2 equations as there is a further reaction for N2)

A

S(s) + O2(g) –> SO2(g)

N2 (g) + O2 (g) —> 2NO(g)
2NO(g) + O2 –> 2NO2 (g)

71
Q

How do both SO2 and NO2 dissolve in water to form acid rain?

A

SO2(g) + 0.5O2(g) + H2O(l) —> H2SO4(l)
4NO2(g) + O2(g) + 2H2O(l) —->
4HNO3 (l)

72
Q

What metal used as a catalyst makes up the structure of a catalytic converter?
And why does it have a honeycomb structure?

A

Platinum/Rhodium/Palladium

Increases surface area and thus reaction rate

73
Q

Equation for a catalytic converter removing Nitrogen monoxide and Carbon monoxide

A

2NO(g) + 2CO(g) —> N2(g) + 2CO2(g)

74
Q

How does a catalytic converter remove nitrogen monoxide and unburnt hydrocarbons? (Just name products)

A

N2, CO2 and H2O

75
Q

Two methods of flue gas desulfurization

Both make CaSO4

A

CaO(s) + 2H2O(l) + SO2(g) + 0.5O2(g) –>
CaSO4.2H2O(s)

CaCO3(s) + SO2(g) + 0.5O2(g) –> CaSO4 + CO2

76
Q

What does catalytic cracking make and what are the conditions and catalyst required?

A

Makes branched alkanes and cycloalkanes
Requires high temp (700K) and moderate pressure
Requires Zeolite Catalyst

77
Q

What does thermal cracking make and what does it require?

A

2 alkenes and 1 alkane (high demand)

Requires high temp and high pressure

Chemistry A Level Key Knowledge (2 decks)

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