Nature's Chemistry Flashcards
Polarity of hydrocarbons
Non polar
What is organic chemistry?
Basically the study’s of compounds containing carbon (with the exclusion of oxides and carbonates)
What are the names and chemical formulas for the first 8 alkanes?
Methane - CH4
Ethane - C2H6
Propane - C3H8
Butane - C4H10
Pentane - C5H12
Hexane - C6H14
Heptane - C7H16
Octane - C8H18
What’s the general formula for the alkane series?
CnH2n+2
What’s an isomer?
Molecules that have the same chemical formula but different structures
What’s an alcohol?
A carbon compound that contains the hydroxyl functional group (OH)
Names and formulas for the first 8 alcohols
Methanol - CH3OH
Ethanol - C2H5OH
Propanol - C3H7OH
Butanol - C4H9OH
Pentanol - C5H11OH
Hexanol - C6H13OH
Heptanol - C7H15OH
Octanol - C8H17OH
General formula for the alcohols
CnH2n+1OH
What is an organic compound?
Compound which molecules contain chains of carbon atoms
Describe the flame produced when ethanol burns
- light blue
- v flammable
- no smoke
Why is ethanol not ionic?
It does not conduct electricity when molten or dissolved in solution
What functional group is found in carboxylic acids?
Carboxyl
What is methanoic acid also known as?
Formic acid
Where is methanoic acid found?
Ant stings and bee venom
Where is ethanoic acid found and used in?
- vinegar
* in the production of plastic and pharmaceuticals
What is ethanoic acid also known as?
Acetic acid
Dehydration and hydration result in ____ molecule
Still one
Condensation results in ___ _____ molecules
Two separate
When are esters made?
When an alcohol and carboxylic acid react together
What would form when ethanol and ethanoic acid react?
The ester ethyl ethanoate
+
Water
What by product is formed in an ester reaction?
Water
What type of chemical is taking place when an ester is formed?
Condensation reaction
What’s the ester link?
The link formed between the carboxyl and hydroxyl groups once water is removed
Explain what the most suitable method of hearing should be used in the making esters reaction
Water bath - chemicals v flammable so not a gd idea to burn over Bunsen
What’s the catalyst in the making esters reaction?
- concentrated sulphuric acid
- specifically the H+ ions
- help remove water
What’s the purpose of the paper towel soaked in cold water in the making esters reaction?
- wet paper = condenser
- cools down the evaporating has so it turns back into liquid and drops back into the boiling tube so none is lost
What’s the purpose of the ceramic wool plug in the making esters reaction?
- stop fumes/ester/ acid/alcohol escaping
* safety
Esters can be split by a ____ reaction to form an alcohol and a _____ ___
Hydrolysis
Carboxylic acid
How is hydrolysis usually carried out?
By heating in the presence of a dilute acid.
The hydrogen ions catalyse the hydrolysis
Reversible
How can you increase the yield of an ester?/ complete hydrolysis of esters?
If the ester is added to a strong alkali eg NaOH and heated under reflux the process can be completed.
ALKALINE HYDROLYSIS
Not reversible
What is produced from the complete hydrolysis of esters?
The alcohol and salt of the carboxylic acid
How can the products of ester hydrolysis be separated?
Through distillation.
The alcohol will be distilled off and the salt of the acid will be left in the flask.
The salt solution can then be acidified with HCl and the salt is converted to carboxylic acid.
Ester uses?
- fragrances
- flavourings
- aspirin (is an ester)
- nail polish/ paint (solvents)
How do esters work as solvents in paint and nail polish?
Keeps liquid and then evaporated out and leaves dry coloured compounds
What medicine is an ester?
Aspirin
What are fats?
Esters formed from 1 molecule of glycerol and 3 molecules of (usually saturated) long chain carboxylic acids
Are fats saturated or unsaturated?
Saturated
Fats have melting points ___ enough to be ___ at room temperature
High
Solid
What are oils?
Esters formed from one molecule of glycerol and three molecules of (usually unsaturated) carboxylic acids.
Are oils saturated or unsaturated?
Unsaturated
Oils have melting points ___ enough to be ____ at room temperatures
Low
Liquids
Fats and oils provide a high source of ___ and help make you feel ___ for longer
Energy
Fuller
What are fats and oils source of?
Fat soluble minerals and essential fatty acids
Sources of fats and oils?
Veg - Olive oil, rapeseed oil
Animal - lard
Marine - cod liver oil
Fats and oils provide essential ___ and ___ acids
Vitamins
Fatty
How is vitamin D produced?
By our skin when exposed to sunlight
How must us Scots get vitamin D?
Rely on consuming foods such as fish, eggs, milk and meat as these contain fats and oils which store vitamin D
How can a vitamin D deficiency affect you?
Affect mental health
What has caused the increased popularity and use of rapeseed?
Used for cooking and producing biodiesel
Under cold conditions what happens to some vegetable oils?
Become cloudy and begin to solidify
How are fats and oils formed?
By a condensation reaction between glycerol with carboxylic acid molecules
Chemical name for glycerol?
Propan-1,2,3-triol
Glycerol is a tri_____
Triglyceride
What shape do fats and oils form?
A tuning fork shape with the limbs of 3 hydrocarbon chains
\_\_\_\_\_\_\_\_\_ | —-——| |\_\_\_\_\_\_\_\_\_
What holds fat/oil molecules together?
London Dispersion Forces
When the fat is heated the Van der Waal’s attractions are easily ____ causing the fat to ___
Broken
Melt
What’s hardening?
The process of hydrogenating an oil to produce a more solid compound
What’s hydrogenation?
The addition of hydrogen to an unsaturated compound eg hydrogenation converts alkenes to alkanes and oils to fats
How are oils converted to fats?
But the use of hydrogen
A nickel catalyst is used during this reaction
Fats and oils are ____ in water
Insoluble
We refer to fats and oils as h______
Hydrophobic