Paper 2 Flashcards
What are the factors that affect the rate of reaction?
Temperature, concentration, surface area, and catalysts.
What does anhydrous and hydrated mean?
Anhydrous) Without water
Hydrated) With water
What happens if in a reversible reaction, the forward direction is exothermic?
The backwards direction is endothermic.
What is equilibrium?
When the rates of the forward and backwards reactions are the same. A revisable reaction in a closed system can reach equilibrium.
What does La Chataliers principle state?
If the forward reaction is exothermic:
- An increase in temperature means a decrease in amount of product
- A decrease in temperature means an increase in the amount of product.
If the forward reaction is endothermic:
- An increase in temperature increases the amount of product
- A decrease in temperature means a decrease in product
What is the formula to work out alkanes?
CnH2N +2
What is the formula to work out alkenes?
CnH2n
What is the equation for complete combustion?
Hydrocarbon+ oxygen —–> carbon dioxide + water
What is the equation for incomplete combustion?
Hydrocarbon + oxygen —-> carbon monoxide + water
What’s the test for carbon dioxide?
Limewater goes cloudy.
What’s the test for water?
White anhydrous copper sulfate turns blue.
How are hydrocarbons separated from crude oil?
By fractional distillation, separated by boiling points. The volume is kept hot at the bottom, and cooler at the top, so the temperature decreases going up the column. The gases move up the tank, and the hydrocarbons condense when they reach the temperature of their boiling points. The different fractions are collected as liquids at different levels.
What is cracking?
Cracking is process of breaking down longer chain hydrocarbons into smaller chain hydrocarbons which are more useful. They’re cracked in a reaction called thermal decomposition.
Can be cracked by
- being passed over a hot catalyst
- being mixed with steam and heated to high temperatures
What is the test for alkenes?
Alkenes are unsaturated, they would turn bromine water colourless.
What are some of the reactions for alkenes?
Reaction with Hydrogen) makes an alkane
Reaction with Halogens) makes a haloalkane
Reaction with Steam) ethane
What is the functional group for alcohol?
- OH functional group
- OL ending
What is the functional group for carboxylic acids?
- COOH functional group
- OLC ending
What is the functional group for esters?
- COO functional group
- OATE ending
What are some natural and synthetic polymers?
Synthetic, Man-Made) nylon, polyester, polystyrene, PVC
Natural) proteins, cotton, wool, starch, silk, DNA
What’s the difference between additional polymerisation and condensation polymerisation?
During condensation polymerisation, a polymer is made, along with a small molecule. Addition polymerisation only has one product, which is the polymer.
What are some polymers made by glucose and amino acids?
Glucose monomer—> starch polymer + water
Glucose monomers —> cellulose polymer + water
Amino acid monomers —> proteins + water
What is a pure substance?
A substance that only contains one element or compound.
-Using the melting and boiling points can determine a pure substance. These are fixed points for pure elements and compounds.
What are the tests for hydrogen, oxygen, and chlorine?
Hydrogen) squeaky pop
Oxygen) relights a smouldering splint
Chlorine) damp blue litmus paper turns white
What are the results for a flame test on metals?
Potassium) Lilac Calcium) Orange Sodium) yellow Barium) green Copper) blue Magnesium) White Aluminium) grey/white Strontium) red
When testing for non-metals by adding nitric acid and silver nitrate, what colour are the precipitates?
Iodine) yellow
Bromine) cream
Chlorine) white
In chromatography, what is the mobile phase and the stationary phase?
Stationary phase) the paper
Mobile phase) the solvent
What is the retention factor in chromatography?
Distance moved by substance
________________________
Distance moved by solvent
What colour are the precipitates for positive ions, using the sodium hydroxide tests?
Calcium) white precipitate forms, doesn’t dissolve in excess
Copper) light blue precipitate, doesn’t dissolve in excess
Iron (11) green precipitate, doesn’t dissolve in excess
Iron (111) red-brown precipitate, doesn’t dissolve
Zinc) white precipitate, dissolves in excess
What’s the test for carbonate?
By adding dilute acid. Carbon dioxide gas is produced, which turns limewater cloudy.
What’s the test for sulfate?
Add dilute acid, then add barium chloride or barium nitrate. A white precipitate forms.
What are some of the advantages and disadvantages of using instrumental methods?
Advantages) more accurate and sensitive, very small substances can be analysed and identified
Disadvantages) tests are expensive, needs special training and equipment.
What are some products of the combustion of fuels?
Nitrogen oxide, articulates (soot), sulfure dioxide, carbon monoxide, carbon dioxide.
What’s the makeup of the atmosphere now?
Nitrogen) 78%
Oxygen) 21%
Other) 1%
What’s the makeup of the atmosphere in the past?
High percentage of carbon dioxide, and water vapour
Traces of methane and ammonia
How has atmospheric levels changed?
Oxygen) increased due to photosynthesis
Carbon dioxide) decreased by dissolving in oxygen or by photosynthesis in early early plants
Water vapour) decreased as the Earth cooled, water condensed and fell as rain to form oceans
Nitrogen) increases from decay and from the breakdown of ammonia.
What’s the effects of global warming?
- Rising temperatures
- Rising sea levels
- Change in weather patterns
- Drought, floods, loss of habitat
What are the stages in sewage treatment?
Screening, primary treatment, secondary treatment, final treatment.
What conditions are need for rusting?
Air, water, and iron
Iron + oxygen + water ——> hydrated iron (111) oxide
How can rusting be prevented?
By root proof paint, oil or grease, plastic, a less or more reactive metal
Galvinised) A thin layer of zinc being added on the surface to prevent rusting.
Sacrificial Protection) a metal more reactive than iron is attached to or coated on an object.
What are the advantages and disadvantages of recycling aluminium?
Advantages) reusable, aluminium is finite
Disadvantages) Lots of energy required to heat to high temperatures
What’s an alloy?
Two or more metals/carbon bonded together to improve the properties of the material, such as strength, resistance to corrosion.
eg) steel, bronze, stainless steel
What are some properties of ceramics?
Brittle, resistant to wear, relatively light, chemically stable, thermal/electrical insulators, high melting points.
- Crystalline ceramics have a regular structure
- Amorphous ceramics have irregular structures
eg) bricks, tiles, pottery
What are composites?
Two or more materials, with one material acting as a binder. The matrix is the binder.
eg) fibre glass, cement, plywood
Where does the nitrogen and hydrogen come from, before they react to form ammonia?
Nitrogen) harvested from the air
Hydrogen) from methane.
methane + steam —–> hydrogen + carbon dioxide
What is the equation for the Haber process?
Nitrogen + hydrogen ———-> ammonia
What are the compromise conditions needed for the Haber process to work?
Pressure is 200 atm
Temperature is 450 degrees C
This means there’s a low yield, of about 5%
What sort of catalyst is used in the Haber process?
Iron
How is ammonia removed after the Haber process?
Removed by cooling the gases so it liquifies, so it can then be separated. Unreacted nitrogen and hydrogen are recycled back into the reaction vessel.
What is bioleaching?
It’s when enzymes or oxidising substances are used to extract metal from ores. It involves bacteria. Made more effect by controlling conditions like pH, temperature and humidity, but takes up to two years and has a low yield. A liquid packed with suitable microorganisms is sprinkled in piles of ore dust.
What is phytomining?
Plants are planted in an area where the minerals are present. The special seeds can take in the mineral metal in as they grow. By burning the plants, the metal can be extracted from the ash that remains.
