Extra Flashcards
Explain why adding a catalyst to the reaction mixture without changing any other conditions can cause a rate of the reaction to increase?
A catalyst decreases the activation energy
State two properties of the collisions between particles that affect the rate of the reaction
The frequency of the collisions
Energy of the colliding particles
What does increasing the volume of the vessel do?
Decreases the pressure
State whether the reaction equation will change if cerium oxide is present in the reaction vessel explain your answer?
No, it won’t because it isn’t used up in the reaction so doesn’t appear in the equation because it is a catalyst
Suggest how you would check whether the results are repeatable?
Repeat the experiments with the same method and compare the results to check that they are similar
Describe and explain with reference to collision theory how the rate of reaction changes during it?
Rate decreases as the amount of reactant fours so does the concentration so the frequency of collisions between the reactant particles decreases
What is equilibrium?
The rate of the forward reaction is equal to the rate of the backward reaction
The forward reaction is endothermic, which two things can you say about the enthalpy change for the reverse reaction?
It is exothermic, so the same amount of energy will be reversed in the reverse reaction has taken in the forward reaction
Suggest to changes that could be made to the mixture so that it would change its colour?
Changing the temperature
changing the concentration
Tip: when there are colours within a reaction, reactants colours, can you mix to create another colour
What do you do when you sketch the reverse reaction?
Swap round the reactants to the graphs so they are the opposite way
What happens when something reaches equilibrium?
When equilibrium is reached the amount of each substance, stop changing and so does the colour
Compare the viscosity of petrol and diesel?
diesel will be more viscous because it has a higher boiling point meaning that is a longer chain and larger molecules
Predictor of a petrol or diesel will be more flammable. Explain why?
Petrol has a lower boiling point, meaning it contains smaller molecules in smaller chains so is more flammable
Fractions boil over a range of temperatures, much narrower than the original crude oil. What does this suggest about the structures of hydrocarbons in a fraction?
Similar number of carbon atoms similar chain length
Suggest two types of useful materials produced from crude oil fractions
Solvent, lubricant, polymers, and detergent
What type of reaction is cracking?
Thermal decomposition/endothermic
Describe how cracking is carried out?
Hydrocarbons are vaporise the vapour is then passed through a hot catalyst, all mixed with steam, and then heated to very high temperatures
What uses are there for alkenes from cracking?
Polymers and starting materials for other chemicals
Explain why and house in fractions of crude or a process for cracking giving chemical equations were relevant?
There’s a high demand for shorter chains because they make good fuel
Longer chains are less useful so less demand
Cracking helps supply short chains
Long chains are heated and vaporised
Vapour passes over a hot catalyst or is mixed with steam to a very high temperature so it’s thermally decomposes
It is useful for fuels and alkanes are used for starting materials for compounds and polymers
When writing, incomplete combustion, what should you do?
Only include the products carbon dioxide, carbon monoxide and water
Explain why the bunk is an important safety precaution when using a Bunsen burner to heat a boiling tube
Hydrocarbons are very flammable. The bong prevents the hydrocarbon vapour from escaping and igniting.
One of the students had a lot more gas in the test to then the others at the end of the experiment suggest an error that occurred
They didn’t fully fail, the test tube of water at the start
Suggest what is important to remove the apparatus from the water when water is sucked back up for the delivery to
Because the hot boiling tube Can crack
Suggest why it would not be possible to carry out this experiment in a lab without a catalyst
It wouldn’t be hot enough and would not be safe to reach the temperature needed so need a catalyst
Why do other compounds in the same homologous series as Ethan react in similar ways?
They have the same functional group
Give three uses of alcohol
Fuels, solvents and drinks
What happens when an alcohol dissolves?
PH 7 and is green
What happens when an alcohol is oxidised?
Forms carboxylic acid
What pH should you have for fermentation?
Slightly acidic, pH
What happens when an alcohol reacts with sodium?
Produces hydrogen
How do you write the formula of an alcohol?
-When there are two alcohol functional groups
C2H4(OH)2
What is needed when you are trying to form an Esta?
Acid catalyst (sulphuric acid)
What are the three functional groups that can react together in condensation polymerisation
Carboxylic, acids, alcohols, and amine
What type of molecule are monomers in starch?
Sugars
Name, one naturally occurring polymers that is made up the same type of monomers are starch?
Cellulose
What is the role of DNA?
Contains all the genetic information for the function of organisms
Describe the general structure of DNA? 4
-Two polymer chains
-made from four different
nucleotide monomers
-linked together by cross links to
-make a double helix structure
Suggest which of these samples with most pure, and why?
Pure substance has a small, arrange and higher melting temperature is and lower boiling point the purer it is
Explain why something is a formulation? 3
-Mixture design to have a precise purpose of each of the compounds.
-It is in a measured quantity that
-contributes to the properties of the formulation.
Name some examples of formulations?
Medicines, cleaning products, fuels, fertilisers metal alloys
Why do substances travel different distances in paper chromatography?
The distance is distributed between the mobile phase and the stationary phase
Why is it necessary to have a little while conducting the paper chromatography experiment?
Stop any solvents from evaporating
What happens to the RF value if the solvent is changed? 2
-Substances have different RF values in different solvents
-as the attraction between the substances and solvent changes
Suggest why I need to spots are shown on the chromatographed shown?
Only two, because the others are similarly distributed between the mobile phase, and the stationary phase so have similar RF values
How do you know how many compounds based on chromatography?
How many spots is how many compound
-If there is still a dot on the baseline, that means there is an insoluble compound in it
What tools do you need to know for calculating the RF value?
Draw to the centre of the spot
Should draw the line from the baseline to the solvent front line
Test for hydrogen?
It must be a burning splint
In an equation for the formation of a white precipitate testing for sulphate, what are the state symbols?
The reactants are AQ
The products are solid
What are two pieces of information that you can get from the flame emission spectroscopy
The identity of the ion
The concentration of the metal ions in solution
How does a flame emission spectroscopy work?
Example is placed in a flame, and as the ion in the sample heat up, they transfer energy as light passing through a Spectorphy, and produces a line spectrum Pacific to that ion
-Producing a line spectra
When this thing out the numbers for the wavelengths in an ion what can make it so it’s difficult to tell?
Some wavelengths, I’m not giving in the table, so it could be from other irons
Approximately how long has the atmosphere been similar to what is today?
200 million years
Compare industry and in the lab?
ammonia and nitric acid to make ammonia nitrate
industry-
-ammonia gas is added to vats contains highly concentrated nitric acid
-very exothermic
-heat realised evaporating water from the mixture make very concentrated ammonium nitrate product
lab-
-smaller scale titration and crystillation
-ammonia solution is used lower concentration so less heat is produced
-crystailsed = pure crystals of ammoniaen nitrate
Products alkanes from fractional distillation?
-3 carbons= LPG (liquifed petroleum gas)
-8 carbons= petrol
-15 carbons= kerosene
-20 carbons= diesel oil
-35 carbons= heavy fuel oil
-40 carbons= bitumen
Properties and reactions of alcohol?
-flammble = co2 and h20
-first four alcohol dissolve in water completely = ph 7 (DONT IONISE LIKE CARBOXYLIC ACIDS)
-sodium= hydrogen
-oxidesd= carboxylic acids
What is molecular and general?
Explain bioleaching?
-bacteria converts copper compounds in the ores to soluble copper compunds
-seperaying from the ore in the process
-leachate solution contains copper ions extracted by electrolysis or displacement reactions with scarp iron
Other naturally occurring polymers?
-portiens-> polypetides-> amino acids (monomers)
-sugars are small molecules contain carbon, oxygen, hydrogen
-> polymerisation form polymers such as starch and cellulose
-starch is an energy store of chemical energy
-cellusoe is polymer in plant cell walls
Name 4 composites?
-wood
-carbon fibers
-fibreglass
-concetre
-propeties depend on matrix/binder and reinformnet
.wood= reinforcement (cellulose fibres), lignin (matrix) strength
.fibreglass= fibres glass (reinforcement) imbed in matrix of plastics low density and is surfboards and boats
.carbon fibers composites have a polymer matrix. reinforcement long chains of carbon atoms with carbon fibres. very strong, light= aerospace, sport cars
.concerte= aggregate (mixture sand and gravel) embed in cement, strong and rigid= building
1)What bonds hold polymers together?
2)properties?
3) why can it be used for clothes?
4)what influences the properties?
1)Colvent
2)-insulators of heat and electricity and flexible
3)-polyesters- clothes stretch and dry easily
4)
-influence properties conditions, monomers
-monomer- determines forces (cross links or not)
-conditions types:
Thermosetting
Therosoftening
How is a poly(ester) formed?
-dicarboxylic acid
-diol
-ester links formed
What catalyst is used in catyltic cracking?
Aluminium oxide
What can alkenes and alkanes make?
Alkenes= polymers, starting for chemicals
Alkanes= fuels
What is poly(Ethene) used for as an example?
HDP and LDP
What does cracking always produce?
-Ethene
What is Thermosoftening?
What is thermosetting?
Weak, intermolecular forces
Covalent an ionic bonds, which are the cross-links
What is low-density Poly(Ethene)?
Low temperature, high pressure can be remoulded
Makes bags and bottles
What is high density poly(Ethene)?
Laura temperature lower pressure and a catalyst
Water, tanks and drainage pipes, very rigid
What are the specific conditions?
-Cracking
-Addition, polymerisation
-Making ethanol fermentation
-Making ethanol, alkenes and steam
-Making ethanol fermentation
-Making esters from condensation reactions
-Condensation reaction, generally
-aimne , groups and amino acids
-cracking cataylitic
-550
-zeolite catalyst
-Cracking steam
-800
-No catalyst
-Addition, polymerisation
-High pressure
-Catalyst
-Making ethanol
-alkenes and steam
= catalyst, and alcohol purified from fractional distillation
-Fermentation
-37
-Anaerobic and yeast catalyst
-Esther condensation
Acid catalyst, sulphuric acid
-condensation reactions, generally
-2 different functional groups
-amine
-Amino acids-> polypeptides-> proteins
How do you make super phosphate?
Phosphate and sulphuric acid
Calcium phosphate Calcium sulphate
How do you make phosphoric acid?
Phosphate and nitric acid
-Phosphoric acid
How do you make calcium nitrate?
Phosphate and nitric acid
Calcium nitrate
Triple superphosphate
Phosphate and phosphoric acid
-Calcium phosphate
How do you make ammonium nitrate?
Ammonium, and nitric acid
Ammonium nitrate
How do you make ammonium phosphate?
Phosphoric, acid and ammonia
Ammonium phosphate
How do you get the raw material, phosphate and potassium?
Phosphate is from mind, rocks and is insoluble in water
Potassium is from mind, rocks, and is soluble in water
How are sedimentary rocks formed?
Matter has been buried compressed over millions of years
How is cool and limestone formed
Coal thick plant deposit
Limestone, calcium carbonate from the shells and skeletons
Why is it difficult to find how the atmosphere around?
Long timescale, so there is a lack of evidence
Suggest why there’s such small months of oxygen in the atmosphere of mars
No photosynthesis as no plants or algae
Two. Potential consequences of the sea levels rising
Flooding and coastal erosion
Suggest how are ice cores can help show how the earths atmosphere changed
Composition of gases, find out the concentration of it at different times
Suggest one limitation of collecting ice cores
Expensive
disrupting environment
Specialist equipment
Suggest two ways that the carbon footprint resulting from an individuals, electricity usage can be reduced
Renewable
Energy-efficient appliances
Suggest one individual might not trying to reduce their carbon footprint
Expensive
Lack of education
Suggest two disadvantages for companies of capturing and storing carbon dioxide
Difficult to find places to store
Needs specialist equipment
Two ways the government can encourage to reduce their carbon footprint
Tax companies that omitting too much
Cap on emissions
Why not:
Affect economic growth and well-being
If a country still developing it could be difficult
Why can the combustion of coal produce sulphur dioxide?
It contain sulphur impurities
What causes global dimming?
Carbon particulates
Two ways acid rain is dangerous
Damage plants and corrode statues
Explain how acid rain is produced
1-Reaction of nitrogen or sulphur with oxygen from the air at high temperatures produced by the combustion engines in cars,
2-producers sulphur dioxide, and nitrogen dioxide, which dissolves in the rainwater, making it acidic
Two problems with nitrogen oxides in the environment
Respiratory problems
And acid rain
What impact do particulates have on human health?
Respiratory problems
What is three ingredients to make soda lime glass?
Limestone, sand and sodium carbonate
Why are borosilicate glass used more?
Higher melting point
What makes LDP and HDP have different properties
Different temperatures and pressures
Catalyst is used in HDP
Describe the general structure of a composite
Fibres and fragments of material as reinforcement
Surrounded by matrix/binder
Bronze steel, brass
Bronze= copper and tin
Steel=iron and carbon
Brass= copper and zinc
One useful, the alloy, brass
-Water taps
Is potable water, pure?
No
Industrial waste water must have further treatment compared to sewage and agricultural waste water suggest why
Contains harmful chemicals
Some life-cycle assessments can be selective in assessing the effects of the product on the environment. Why?
Only shows elements that support the companies claims, so it is positive advertisement
What is galvanising?
coating iron with zinc as it is more reactive than iron so if it is scratched,
-it will still stop it from corroding
What does the term corrosion mean?
Reaction of a material with a substance in its environment, gradually destroying it
Why isn’t corrosion a problem? Things made an aluminium
Oxide forms when aluminium reacts with a protective layer, preventing chemicals from reacting with it
What is meant by the term renewable resource?
a resource that reforms to a similar rate that humans can use it
What is stainable development?
Need it for the present society would not damaging future generations
Explain how chemist play a role within sustainable development
Adapt processes uses less resources to the environment
E.gcatalyses reduce the energy needed
Give two reasons why recycling can be more sustainable than making new materials?
Less energy
Conserves raw materials
Material that is, commonly recycled and describe the process? 3
Glass
-seperated from colour and chemical compounds within
-Crushed and melted down from of a glass products
-remoulded
Copper metal can be extracted from the product pthyomining
-Electrolysis solution, containing copper compounds
-Displacement reactions using scrap iron
Explain how phytomining is used to produce the substance
-Growing in soil containing copper
-so copper buildup in the leaves and then it’s burnt=
-ash so it has copper compounds in it
-soluble copper when dissolved in acid
Find a method to sample of potable water from seawater
Pour salt, water into a flask of a tripod
Connect condenser to a supply of cold water
Goes in the bottom of the tub
Heat the flask in the water to boil
Collect the water running out of the condenser into the beaker
Which line in figure one represents the reaction that runs at the highest temperature why
the line that is the most steep on the graph because the temperature increases the rate of the reaction
Name, two compounds of potassium that is used to make NPK fertilisers
-Potassium chloride,
-potassium sulphate
Direction in the industry is carried out at a much higher concentration then in the lab why
Lower concentration is safer to carry out
Trubity?
Cloydlyness
What are ceramics?
-non metallic. Soilds
-high melting points
-non carbon based compunds
-good insulators heat and electricity
-brittle
Alkanes small chains properties? 3
-boiling points low
-very flammable
-low viscosity
Alkanes large chain properties? 3
-boiling points high
-very difficult to ignite
-high viscosity
