Name the main atmospheric pollutants and their danger.
- Carbon monoxide - Poisonous gas.
- Carbon dioxide - Causes green house effect
- NO is a respiratory irritant.
- NO2 reacts with unburnt hydrocarbons to produce low level ozone.
- Sulfur dioxide - A contributor to acid rain.
Give ways of dealing with polymer waste.
- Sorting polymers and recycling them(through reclamation).
- Use waste polymers as a fuel source to generate electricity.
- Turning polymers into synthesis gas which can be used as chemical feedstock for conversion into useful products.
- Making polymers from renewable material which break down naturally in the environment to form CO2 and water.
Give uses of alcohols.
- Ethanol used in alcoholic drink,aftershaves and perfumes.
- Ethanol blended with petroleum to increase octane rating.
- Methylated spirits - Mix of ethanol with small amounts of methanol and dye to produce methylated spirits which is used as a solvent for removing paint or as spirit burners in camping.
- Methanol can be used as a clean burning fuel.
- Methanol used in the feedstock industry.
- Methanol can be formed from biomass, so can be a carbon neutral fuel.
In order to perform controlled tests in hydrolysis what should remain the same.
- Use equal amounts,in mol, of each halogenoalkane.
- Use halogenoalkanes of the same chain length.
- Use water bath to ensure constant temperature .
Name the uses of CFC's that now can't be done with CFC's.
- Blowing agents
- Solvents( for the dry-cleaning industry)
Name the molecules that have now replaced CFC's.
- HFC's - hydrofluoroalkanes.
- HCFC's hydrofluorohydrocarbons .
- butane - (flammable though)
Give reasons why 100% percentage yield is usually not achieved.
- Reactions may be at equilibrium and never go to completion.
- Other side reactions may occur, leading to by-products.
- Reactants may not be pure.
- Some products/reactants left in apparatus.
- Seperation and purification may result in loss of product.
What factors does the amount of vibration of a molecule after absorbing infrared radiation depend on?
- Bond strength
- The mass of each atom involved in each bond.
List the applications of infrared spectroscopy.
- Forensic science
- monitoring the degree of unsaturation in polymers.
- quality control in perfume manufacture
- drug analysis.
List the uses of mass spectrometry.
- Identifying unknown compounds.
- To determine the abundance of each isotope in an element.
- Detecting banned substances such as steroids in athletics.
- Analysing molecules in space.
- Detecting traces of toxic chemicals in contaminated marine life.
State factors which cause the experimental value of enthalpy of combustion to be less than the true value?
- incomplete combustion
- heat loss to surroundings.
- specific heat capacity of apparatus not calculated.
What can affect the rate of a chemical reaction?
- Surface area
List the advantages of using a catalyst in industrial processes:
- Saves energy and therefore costs as well as fuel being burnt.
- Allow processes to occur with less by-products formed hence there is less waste for the companies and less costs in seperation techniques.
What are the advantages of enzymes over catalysts?
- Enzymes work at milder conditions such low temperatures and pressures and an optimum pH.
- Enzymes are biodegradable while some catalysts are quite toxic at the end of their industrial lifes.
State the conditions for the ammonia process.
- Iron catalyst.
- Temperature of 400 *C.
- Pressures of 200 atmospheres.
What are the top three greenhouse gases?
What are some strategies to combat climate change?
- Cleaner cars.
- International coorperation ( through agreements to reduce pollution by a certain date/ awerness to public/ have scientists share their ideas.)
- CCS ( carbon capture and storage )
- Alternative energy sources ( solar/wind)
Give different uses of CCS.
- Store CO2 in old oil and gas fields.
- Store as carbonates (react CO2 with metal oxide)
- Store CO2 in porous rocks and seafloor.
Write out all the steps from the formation of ozone to the destruction of ozone.
- O2 ---> 2O
- O + O2 --> O3 + heat
- O3 + (Uv <320nm ) --> O2 + O
Overall: O3⇔ O2 + O
- O + O3 --> 2O2
List the types of catalytic converters and their uses.
- Oxidation catalysts, used in diesel cars. Oxidise carbon monoxide to CO2 and sure hydrocarbons fully react with oxygen.
- Three-way catalysts - fitted into petrol engines:
2NO + 2CO --> 2CO2 + N2