C7 Biological Chemistry Flashcards
What is the simplest organic compound?
A hydrocarbon
What is a hydrocarbon?
Any compound formed from carbon and hydrogen atoms only
What is an alkane
- The simplest type of hydrocarbon
- Saturated compounds (each carbon atom forms 4 single bonds)
What are the first four alkanes?
Methane, ethane, propane, butane
What happens to the hydrocarbon properties as the chain length gets longer?
- Higher viscosity
- Higher BP and MP
- Lower flammability
What is the complete combustion reaction for hydrocarbons?
Hydrocarbon + Oxygen
-> Carbon dioxide + Water
What is one use for a hydrocarbon?
Used as a fuel
What is crude oil?
A fossil fuel formed from ancient biomass that has been under pressure and high temperature for millions of years
What does non renewable mean?
It is a finite resource
How does fractional distillation work?
- The oil is heated until most of it has turned in to a gas
- In the column there is a temperature gradient
- The longer hydrocarbons have high boiling points, meaning they condense and drain out of the column early on; The short hydrocarbons have lower BP so they condense and drain out at a later time
What is cracking? What are the conditions needed in this process?
The breaking of longer chain hydrocarbons in to shorter ones. High temperature and a Catalyst
As well as alkanes, what else does cracking produce?
Alkenes
What are the two different types of cracking?
Thermal cracking and catalytic cracking
What are Alkenes
Hydrocarbons which have a double bond between two of the carbon atoms in their chain
What are the first four alkenes?
Ethene, Propene, Butene, and pentene
Why is there no Alkene with one carbon atom?
Because alkenes need a double carbon bond to be classified as an ethene
What is the standard reaction for the incomplete combustion of ethenes in air?
Alkene+ Oxygen -> Carbon + Carbon monoxide + Carbon dioxide + Water
How can the addition of bromine to a double bond be used to test for alkenes?
- When orange bromine water is added to a saturated compound, like an alkane, no reaction will happen and it will stay bright orange
- If its added to an alkene the bromine will add across the double bond, making a colourless dibromo- compound- so the bromine water is decolourised
What are plastics made out of?
Made up of polymers
What is polymerisation?
The joining of small monomers to form a polymer
What type of bond do monomers have that make up the addition polymers?
A double carbon bond
What is an alcohol?
A homologous series of organic compounds
What are the first four alcohols in the homologous series?
Methanol
Ethanol
Propanol
Butanol
What are alcohols uses
- Fuel
- Solvents
- Drinks
What is the process of fermentation?
Using sugar and the enzyme yeast, you can make ethanol + Carbon dioxide
What are carboxylic acids?
A homologous group of compounds that all have -COOH as a functional group
What are the first four carboxylic acids?
Methanoic acid
Ethanoic acid
Propanoic acid
Butanoic acid
How do carboxylic acids react with carbonates?
Ethanoic acid + Sodium Carbonate -> Sodium ethanoate + water + carbon dioxide
What functional group do esters have?
They have the functional group of COO
How are esters made?
Formed from Alcohol and a carboxylic acid
What is the formula for making a ester?
Alcohol + Carboxylic acid -> Ester + Water
What is condensation polymerisation?
- involves monomers which contain different functional groups
- Monomers react together and bonds form between them, making polymer chains
- For each new bond between them, a small molecule ( Water) is lost
What are examples of naturally occurring polymers?
- DNA
- Proteins
- Starch
- Cellulose
What are the monomers that protein is made up of?
Proteins are made up of chains of amino acids
What are the two different functional groups in amino acids?
- A basic amino group
- An acidic carboxyl group
What are the monomers that DNA is made up from?
Nucleotides
Why is bitumen not used as a fuel?
Because the hydrocarbon chain is long, the properties are:
- High viscosity
- High boiling point
- Low flammability
Why are longer hydrocarbon chains cracked to make shorter hydrocarbon chains?
- They have a greater demand
- They are more useful
- Better fuels
- Used to make polymers and alkenes
What kind of reactions are ethane and ethene involved in?
- Both react with oxygen in complete combustion reactions to produce water and carbon dioxide
- ethene decolourises bromine water but ethane doesnt
- Ethene is more reactive than ethane
- Ethene can react with hydrogen, water, halogens, and can undergo addition reactions
- Ethene can also polymerise to produce polyethene
Why does carbon dioxide make lime water turn cloudy?
They react which forms a white precipitate of solid calcium carbonate causing it to be clouded
What kind of catalyst is needed to enable a reaction between carboxylic acids and alcohols? What does it form?
You need an acid catalyst and it will form a pleasant smelling compound like an ester
How can you tell from an ionisation reaction if an acid is weak?
If its reversible it is a weak acid because there would only be a partial ionisation ( Some of reactants not ionised)
What happens when you react Ethanol and Ethanoic acid?
Ethyl Ethanoate + Water
