Studied by 0 people
Mass spectometer
Instrument that can seperate isotopes of an element based on their mass-to-charge ration, used to determine the relative isotopic mass.
It shows the number of isotopes present in an element, their relative isotopic masses and their proportions
Crude oil, How is hydrocarbon obtained from crude oil. Why is crude oil renewable or non-renewable?
Decaying prehistoric marine microorganisms became part of Earth's crust. Over time high temperatures and pressures formed crude oil.
Crude oil undergoing fractional distillation, separating hydrocarbons based on their boiling points.
Non-renewable can not be replenished at the rate of use.
Finite availability means it is in limited supply and will eventually be used up.
Describe one way hydrocarbons are made.
Made from natural sources from the process of crude oil undergoing fractional distillation, separating hydrocarbons based on their boiling points.
Biomass
Organic material from living or recently living organisms.
It can be used for fuel or raw materials.
Wood - biomass
Plant-sourced biomass
Plant-sourced biomass refers to carbon-based material that has come from plants.
Plants can offer an alternative renewable source of organic chemicals.
Can offset carbon emissions
Cheaper doesn’t require machinery and can limit waste
Isomers
- Molecules with the same molecular formula but different structural arrangements.
Different physical and chemical properties.
State 3 properties of hydrocarbons.
Non-polar
Increase size = increase flash point. Flash point is the lowest temp at which a liquid forms sufficient vapour to ignite.
Increase size = increase boiling point. More dispersion forces
Increase size = increase viscosity ( thickness)
Larger molecules or longer chains in a liquid increase its viscosity because they tend to tangle together and have stronger attractions between molecules, hindering the flow of the liquid. Higher viscosity liquids are thicker and flow more slowly.
Haloalkanes (include def, solubility, mp and bp, use and formula)
Halogen replaces a hydrogen to carbon bond in a hydrocarbon.
This increases the boiling and melting point, as the presence of the halogen forms a dipole-dipole bond, which requires more energy to break.
Though the halogen is polar, the solubility decreases as the chain length increases, due to the influence of the non-polar part of the molecule.
Use: Refridgerants
Why is the boiling points of haloalkanes higher than for alkanes of the same carbon chain lenth?
Because of the addition of halogen which makes the halogen-carbon bond polar since it is a dipole-dipole bond which requires more energy to break the bond.
Can haloalkanes undergo substitution reactions?
Haloalkanes can undergo substitution reactions, where the halo functional group is replaced by another functional group, such as -OH.
This is because haloalkanes are particularly reactive in substitution reactions due to the presence of the halogen atom, being more electronegative and takes electrons with it when leaving the molecule.
Describe the boiling points and solubility of alcohols.
High boiling point due to - OH group which is a hydrogen bonding and strengths the intermolecular bonds. It increases as size increases, due to more intermolecular bonds.
The hydroxyl group is polar.
The solubility of alcohols in water decreases the longer the chain gets...a longer chain means that more of the molecule becomes non-polar.
Describe the boiling points and solubility of carboxylic acid.
The boiling point increases as the size increases due to more intermolecular forces, C=O and the strong hydrogen bonding in the carboxyl group.
The solubility of carboxylic acid in water decreases the longer the chain gets...a longer chain means that more of the molecule becomes non-polar.
Compare the bp of carboxylic acid, alcohols and haloalkanes.
Carboxylic acids have a higher bp compared to alcohols as there is a hydrogen bond (OH) and a C= O, having more intermolecular forces. While alcohols only have a OH which is a hydrogen bond.
Haloalkanes have weaker dipole-dipole interactions compared to carboxylic acids and alcohols, leading to weaker intermolecular forces and lower boiling points.
Natural and synthetic polymers
Synthetic polymers- Synthetic polymers are made from raw materials obtained from fossil fuels or from biomass. plastic
Polymers are usually made by either addition or condensation polymerisation.
Addition polymers are formed when an addition reaction causes monomers containing carbon-to-carbon double bonds to be broken and link together.
Condensation polymers are formed when molecules combine to form a larger molecule and a small molecule (such as H2O) is produced as a by-product.
Compare thermosetting plastics and thermoplastics.
Thermoplastic polymers are recyclable because they turn to liquid when heated allowing them to be remoulded, this is because they have weak intermolecular forces between the long chains. Thermosetting polymers aren’t recyclable as they would be burnt or char when heated, this is because they have strong convalent bonds between the long chains.
Thermosetting plastics
Thermosetting plastics are polymers that undergo irreversible crosslinking, strong convalent bonds to form rigid and durable structures.
Elastomers
Materials that can be stretched due to a small amount of cross- linking but return to their original shape when the stretching force is removed.
Monomer
small molecules that are able to react to form long chains of repeatings units.
Additional polymerisation
The process in which monomers with a carbon-to-carbon double bond or triple bond is broken, allowing them to react and form long chains of repeating units.
Condensation polymerisation
The process in which a functional group of one monomer reacts with a functional group of another monomer. During this reaction, a small molecule, often water, is released.
Remember to have open bonds at the end, include brackets and n (for number of monomers)
Hydrolysis
The chemical breakdown of a compound due to reaction with water.
Note 
Flashcard (22)