What's in a medicine? Flashcards
1
Q
What’s the General formula for an alcohol?
A
ROH
2
Q
What’s the structural formula for an alcohol?
A
R-OH
3
Q
What’s the suffix for an alcohol?
A
-ol
4
Q
What’s the general formula for an aldehyde?
A
RCHO
5
Q
What’s the structural formula for an aldehyde?
A
R-C=O
/
H
6
Q
What’s the suffix of an aldehyde?
A
-al
7
Q
What’s the general formula for a ketone?
A
RCOR’
8
Q
What’s the structural formula for a ketone?
A
C with two R groups attached on one side and a double bonded O on the other
9
Q
What’s the suffix for a ketone?
A
-one
10
Q
What’s the general formula of a carboxylic acid?
A
RCOOH
11
Q
What’s the structural formula of a carboxylic acid?
A
C with an R- attached on one side and a double bonded =O and an -OH on the other side
12
Q
What’s the suffix for a carboxylic acid?
A
-oic acid
13
Q
What’s the general formula for an acid anhydride?
A
(RCO)2O (2 is subscript)
14
Q
What’s the structural formula of an acid anhydride?
A
R-C-O-C-R’ with a double bonded O coming off each carbon.
15
Q
What’s the suffix for an acid anhydride?
A
-oic anhydride
16
Q
What’s the general formula for an ester?
A
RCOOR’
17
Q
What’s the structural formula for an ester?
A
R-C-O-R’ with a double bonded O on the C
18
Q
What’s the suffix for an ester?
A
-oate
19
Q
What’s the general formula of an ether?
A
ROR’
20
Q
What’s the structural formula for an ether?
A
R-O-R’
21
Q
How do you name an ether?
A
name of shortest alkane oxy name of longest alkane e.g. methoxyethane
22
Q
What are the three types of alcohol?
A
Primary,Secondary,Tertiary
23
Q
What’s a primary alcohol?
A
One where the hydroxyl (OH) group is bonded to a carbon which only has one other carbon bonded to it
24
Q
What’s a secondary alcohol?
A
One where the hydroxyl (OH) group is bonded to a carbon which has two other carbon atoms bonded to it
25
What's a tertiary alcohol?
One where the hydroxyl (OH) group is bonded to a carbon with three other carbon atoms bonded to it
26
What oxidising agent is used to oxidise alcohols?
Acified Potassium Dichromate (VI)
27
What can primary alcohols be oxidised to?
Aldehydes THEN Carboxylic acids
28
What can secondary alcohols be oxidised to?
Ketones
29
What can tertiary alcohols be oxidised to?
DUKED!- they can't be oxidised!
30
When the dichromate is reduced. what changes are observed?
Solution turns from Orange to Green
31
How do you just get an aldehyde from a primary alcohol?
Heat the alcohol gently with the potassium dichromate (VI) and sulfuric acid in a flask with distillation apparatus so when the aldehyde evaporates, it's cooled and condensed.
32
How do you get a Carboxylic acid from a primary alcohol?
Heat the alcohol with the potassium dichromate (VI) and sulfuric acid under reflux.
33
How do you get a Ketone from a secondary alcohol?
Heat the alcohol under reflux with Potassium dichromate (VI) and sulfuric acid.
34
How can an alkene be formed from an Alcohol? (the word used to describe)
Dehydration/ Dehydrated
35
What is a dehydration reaction?
Where water is eliminated
36
Briefly, what are the two ways of dehydrating an alcohol?
with pumice/ aluminium oxide
or
Reflux and heat with excess concentrated sulfuric acid
37
Describe how you would dehydrate an alcohol using pumice/aluminium oxide
Place the alcohol vapor over a hot catalyst of either pumice or aluminium oxide
38
Describe how you would dehydrate an alcohol using Sulfuric acid
Reflux alcohol with excess concentrated sulfuric acid at 170 degrees Celsius.
39
What's happening in the sulfuric acid method of dehydrating an alcohol?
The hyroxyl group on the alcohol will bond to the H+ ion from the conc. acid. The alcohol gains a H and the oxygen gains a positive charge
The positively charged oxygen will pull electrons away from the neighbouring carbon, and water will be eliminated, creating an unstable carbocation intermediate.
The carbocation then loses H+ and the alkene is formed.
40
In which 2 ways can alcohols form esters?
reacting with carboxylic acids
or
with acid anhydrides
41
How would you make an ester with alcohol and carboxylic acid?
Heat together in presence of an acid catalyst (conc. sulfuric or hydrochloric acid
42
What do you call the reaction between Carboxylic acid and alcohol?
Esterification and condensation
43
What sort of reaction forms haloalkanes from alcohols?
Substitution reactions (where the halogen replaces the OH group)
44
How do you make a haloalkane from an alcohol in the lab?
Shake the alcohol with the compound which contains halide ion(s) e.g. HCl
45
What are phenols?
Benzene rings with -OH groups attached
46
How do you test for a phenol?
Add to neutral Iron (III) Chloride and shake. Will turn purple if a phenol is present. Purple= Phenol
47
How would you describe the acidity of phenols?
They're weak acids
48
Do phenols react with weak alkalis? why?
nope. They are not strong enough bases to remove the hydrogen ion from the phenol
49
Do phenols react with strong alkalis?
yep
50
What's formed when phenols dissolve in water?
A phenoxide ion and a H+ ion
51
Phenol + strong alkali -->
Salt+ Water
52
Phenol + Sodium Hydroxide Solution -->
Sodium Phenoxide + Water
53
How can you tell Phenols apart from Carboxylic acids?
Phenols don't react with carbonates, Carboxylic acid does- which produces Carbon Dioxide
54
How can you make an Ester from a phenol?
React with an Acid Anhydride (makes ester and carboxylic acid)
55
How can you tell a phenol and alcohol apart?
Phenols don't react with Carboxylic acid, Alcohols do
56
What's the purpose of refluxing?
It ensures you don't lose any volatile organic substances.
| This means if you put them only a Bunsen burner, they'd evaporate or catch fire and won't react.
57
How do you reflux a reaction?
Heat the solution in a flask fitted with a vertical Liebig condenser (which cools and condenses vapour). Heat the solution electronically (to avoid naked flames).
58
What's the purpose of distillation?
To separate substances by their boiling points + prevents further reactions
59
How does distillation work?
Once a chemical boils, it vapourises, causing it to evaporate upwards and into the condenser which cools it using water- therefore condensing it and it can be collected as a liquid in a beaker at the end of the condenser.
60
What happens in redistillation?
When the product still contains impurities after distillation, the impure product can be distilled again and when the mixture reaches the temperature the product you want boils at, it will be collected. If the temperature changes, then you can remove the flask and leave the impurities separate.
61
What's the purpose of separation?
Removes any water soluble impurities from the product
62
How is separation done?
You pour the impure product into the separating funnel and add water. Then shake and leave to settle. The organic layer is less dense so will sit on the top and the aqueous layer will be below and can be tipped out by removing stopper at the bottom of the funnel.
63
Why do you dry a purified product?
To remove any water left after separation
64
How do you dry a purified product?
Add anhydrous salt e.g. Calcium Chloride which will bind to any water present to become hydrated. When you first add it, it will become lumpy, but if you leave it longer the mixture will look like a snow globe. You can filter to remove the solid.
65
What's the purpose of filtration?
It isolates solid organic products
66
How do you filter?
Pour the reaction mixture into a Buchner funnel with filter paper in. How the funnel there should be a side arm flask (a flask with an arm), This should be attached to a vacuum line which forces liquid through the funnel leaving the solid on the filter paper.
67
What's the purpose of recrystallisation?
To purify organic solids formed from a reaction
68
How do you recrystallise something?
Add a very hot solvent e.g. hot ethanol, to the solid, until it just dissolves- don't add too much solvent. Leave the solution to cool down slowly. Crystals of the product should form during cooling. Impurities will stay in solution. You can then remove the crystals by filtration. Then wash them with an ice-cold solvent and then dry
69
Why is your solvent choice important for recrystallisation?
If your product isn't soluble enough for the solvent, it won't be able to dissolve it. If it's too soluble, most will stay in solution, even after cooling, giving a low yield.
70
What's the purpose of measuring melting point?
It determines purity of an organic solid
71
How do you go about measuring the melting point of an organic solid?
Pack a small sample of solid into a glass capillary tube and put inside the heating element. Increase the temperature until the solid turns to liquid. A melting range is measured from when it starts to melt until it's fully melted. You can look it up in a data book to compare.
72
How do impurities in a substance affect the melting point?
Lower it and increase the range.
73
What's the purpose of Thin Layer Chromatography (TLC)?
It separates mixtures
74
Describe how you go about doing thin layer chromatography?
Draw a line on the TLC plate in pencil and put a drop of each mixture to be separated on the line. Place the beaker in a small amount of solvent, with the solvent below the baseline. Leave until the solvent has almost reached the top of the plate. Draw the line showing where the solvent got up to.
75
In TLC what's the mobile phase and what's the stationary phase?
Mobile phase= solvent
| Stationary phase= TLC plate
76
How can you see colourless chemicals on the TLC plate?
Either use a TLC plate with fluorescent dye added and use a UV light to see the separated chemicals.
Or expose them to iodine vapour which shows the spots as purple.
77
Other than separating small amounts of substances, what else can TLC be used for?
It can be used to purify substances, by separating larger amounts.
78
How would you go about using TLC to purify substances?
you use a burette packed with silica/ alumina (stationary phase). Then pour your mixture in and run the solvent though it (mobile phase) . This separates the chemicals as they come out of burette at different times.
79
How do you work out the number of chemicals present in the mixture you used TLC on?
Count the number of spots
80
How do you work out what each chemical on the TLC plate is?
Work out the Rf value. Rf= distance travelled by spot/ distance travelled by solvent. You can then look in data book to find chemical from its Rf
81
What's happening during Infrared Spectroscopy?
A beam of IR radiation is passed through a sample of a chemical. It's then absorbed by the covalent bonds, increasing their vibrational energy. Bonds between different atoms vary in how much they vibrate allowing you to work out the functional group from the spectrum it produces.
82
What are the two uses for Mass Spectrometry?
- To find the relative isotopic abundances of an element
| - To get a mass spectra for molecular samples to identify structure and molecules
83
What's the Molecular ion peak?
The peak with the second highest mass/charge ratio. It tells you the mass of the whole molecule
84
What's the M+1 peak?
A peak caused by the presence of the Carbon-13 isotope
85
How would you use a mass spectrum to work out the structure of a molecule?
Identify what each of the fragments are/ could be. Piece them together to form a molecule with the correct Mr (using the Molecular ion peak)
86
How are fragments formed in the Mass Spectrometer?
Being bombarded with electrons breaks some of the Molecular ions break up into fragments.
87
When writing fragments, what must you always remember?
give them a + charge e.g. CH3+
88
What does it mean to be sustainable?
Meeting today's needs without jeopordising future generations by using up all the earth' resources.
89
What are the three main principles of green chemistry?
- Use renewable resources
- Ensure all the chemicals and processes involved are as safe as possible
- Make sure waste is minimised and products are biodegradable or recyclable
90
How is it possible to use renewable resources in the chemical industry?
- use raw materials where possible e.g. plant based products
- Use renewable energy e.g. solar power
- If it's not possible to use renewable energy, energy usage should be minimised
91
How is it possible to Ensure all chemicals and processes involved are as safe as possible in the chemical industry?
- Use non- toxic non- environmentally damaging reactants and products.
- Use chemicals and processes which aren't dangerous e.g. no risk of explosion
- Improvement of technologies which monitor and control hazardous processes.
92
How is it possible to make sure waste is minimised and products are biodegradable or recyclable?
- ensure atom economy is high (more of reactants are turning to products instead of waste)
- Use catalysts where possible
- Avoid unnecessary steps
- biodegradable products
