Organic Chemistry and the Uses of Chemicals Flashcards
What is the order of names of prefixes in alkanes, alkenes, alcohols, and carboxylic acid?
Meth Eth Prop But (Pent)
What is the functional group of alcohols?
-OH
What is the general formula of alcohols?
CnH2n+1OH
How can you turn an alcohol into a carboxylic acid?
Oxidise it using an oxidising agent
What is the functional group of carboxylic acids?
-COOH
What is the general formula of carboxylic acids?
Cn-1H2n-1COOH
What is the formula for fermentation?
C6H12O6 –> 2C2H5OH + 2CO2
What is a homologous series?
A family of molecules which have the same general formula, functional group and similar chemical properties
How can you make a solution of ethanol by fermentation?
Mix yeast and a solution of a carbohydrate e.g. glucose in a clean container. Seal it and leave it at a temperature between 30 and 49 degrees C. When the concentration of alcohol reaches 10-20%, the reaction stops as the yeast gets killed by the alcohol. The yeast falls to the bottom of the container and you can take the ethanol solution from the top.
How can you reach ethanol concentrations of more than 20%?
Use fractional distillation: ethanol has a lower boiling point that water, so it evaporates and rises up the column while the water stays liquid. Condense the ethanol vapour with a Liebig condenser and collect it in a flask.
How would you investigate how good different alcohols are as fuels?
Put some alcohol in a spirit burner using gloves and measure its mass
Measure 100cm^3 of distilled water into a copper calorimeter. Use a draught excluder, put a thermometer in, and put an insulating lid on
Record the initial temperature and light the wick. Stir the water throughout with the thermometer and blow out the burner when temperature rise reaches 20 degrees C.
Reweigh the burner and repeat with different alcohols
What is the trend of alcohol efficiencies as fuel?
The longer the carbon chain, the more efficient the alcohol
What are nanoparticles?
Particles 1-100 nanometers (1x10-9 m) across, such as fullerenes. They have different properties from the bulk chemicals they are made from.
Why do nanoparticles have different properties to wider particles?
They have a larger surface area to volume ratio, so a much greater proportion of their atoms are available to interact with other substances.
What are some uses of nanoparticles?
Catalysts
Cosmetics such as sunscreens as they have better protection and do not leave white marks
Nanomedicines e.g. delivering drugs as they are absorbed more easily
Tiny electric circuits
Making plastics in sports equipment more durable
Silver nanoparticles are added to surgical masks and wound dressings as they have antibacterial properties
What are some problems with nanoparticles?
We do not know all the side effects or long term health impacts yet
Some nanoparticles used in medicine do not break down easily so could start to build up in cells
Some could cause lung inflammation if breathed in
What are some different polymers and their uses?
Strong, rigid polymers e.g. high density poly(ethene) are used to make water pipes
Light, stretchy polymers e.g. low density poly(ethene) are used for plastic bags and bottles
Poly(styrene) foam is used as packaging and as a thermal insulator
Heat resistant polymers such as melamine resin and poly(propene) are used in plastic kettles
What are ceramics and some examples?
Materials made by baking substances to produce a brittle, stiff material. Clay can be hardened at high temperatures and used as a building material such as bricks.
Glass, made by melting and cooling limestone, sand, and sodium carbonate, is transparent and strong
What are composites and some examples?
Materials made of one material (the reinforcement) embedded in another (the matrix or binder). Carbon fibre composites use carbon atoms held together in a polymer resin matrix. They are strong and light and used in sports cars and aerospace
What are advantages and disadvantages of polymers, ceramics, metals, and composites?
Polymers - adaptable, cheap, less dense, insulators. Can degrade and break down
Ceramics - insulators, strong, hard wearing, don’t degrade or corrode. Brittle and stiff
Metals - good conductors, malleable, some corrosion resistant, less brittle. Can deform, some corrode
Composites - versatile. Expensive
What is condensation polymerisation?
Polymerisation usually involving two different types of monomer, which react and form bonds, making chains. Each monomer must contain at least two functional groups, one at each end, which form bonds, losing small molecules at the same time.
How are polyesters created?
They form when dicarboxylic acid monomers (two -COOH groups) and diol monomers (two -OH groups) react, forming an ester link. Molecules of water are lost.
What are some natural polymers and their monomers?
DNA, made from 4 different nucleotides
Proteins, made from amino acids
Starch and cellulose: large carbohydrates made from smaller carbohydrates (sugars), which contain carbon, oxygen, and hydrogen
What is a life cycle assessment?
An assessment looking at each stage of the life of a product, working out the potential environmental impact at each stage.
