C2 Flashcards
Why metals can be bent and hammered into different shapes (1)
Made of layers which can slide over each other
Electrolysis (2)
Electricity Passed through ionic substances
Sodium chloride negative electrode
Hydrogen
Why graphite conducts electricity (2)
1 electron from each atomIs delocalised
Exothermic (1)
Gives out heat
How ions are held together in solid magnesium oxide
Opp charged ionsAttract
Hydrochloric acid + magnesium oxide turns into ? + water (1)
Magnesium chloride
Soluble compound contain bromide ionsDitto silver ions (2)
Sodium bromideSilver nitrate
Why lights turned out (1)
Silver ions reduced to silver
Type of chemical reaction when compounds mixed (1)
Precipitation
Reduction (2)
Electrons gained
How decrease in temp affect yield of ammonia (2)
DecreaseRate of reaction slower
Increase in pressure affect ammonia yield (2)
IncreaseIncrease RoR
Economic safety and environmental factors when ammonia factory near town (3)
EconomicLarge town provides work forceWorkers not travel far to workSafetyEscape of dangerous gasesDanger of increased trafficEnvironmentalEye sireLoss of habitants
How nucleus of oxygen 18 diff from 16 (2)
2More neutrons
How did wohler prove that a life force is not needed to make organic compounds (1)
He made organic compounds
Why most scientists still believed life force needed to produce organic compound (1)
Wohler lack of status
Why most scientists believe wohler (1)
Wohler had more evidence
Lead an what makes lead nitrate (1)
Nitric acid
How solid lead nitrate obtained from lead nitrate solution (1)
Evaporate
Exothermic. How temp will change as reaction occurs (1)
Increases
Why giant covalent structures have high melting points (2)
Strong bondsLot of energy needed to break them
Why increasing temp increases RoR (2)
Particles have more energyMove fasterCollide more often
Nanosize (1)
1-100nm
Why nanocoated tennis balls good for environment (2)
Less need to be madeLast longerLess wasteLess pollution
How vapour pressure of propane changes with temp (2)
No change initiallyIncreaseSlowly at first then more rapidly
Why propane low bp(2)
WeakIntermolecular forces
How metals conduct electricity (2)
Electrons free to moveAnd carry charge
Why gel contain ions can conduct electricity (1)
Ions are charged
Why did the mass of the flask and contents decrease with time (1)
Loss of CO2
Why not get max amount of aspirin (1)
Errors in weighingImpure reactants
How catalyst reduce cost (1)
Use lower tempUse less fuel
Alkali formed in electrolysis of sodium chloride solution (1)
Sodium hydroxide
…..Cl- turn into Cl2 …………. (1)
2 +2e-
How sodium atom change into ion (2)
1 electron given away
Why chloride ions move to positive electrode (1)
Ions are negatively charged
Why done by independent scientists (1)
Not biased
Property of hydrogen chloride allow it escape into atmosphere (1)
Gas
Insoluble solids separated from solution how (1)
Filtration
Crystals obtained from solution how (1)
Evaporation
Simple molecules have low bp why (2)
WeakIntermolecular forces
Diff between H2 atom and H1 (2)
H2 1 proton and 1 neutronH1 1 proton
Why copper has high mp (4)
Giant latticeStrongElectrostatic forces of attractionLots of energy needed to break the bonds
Why student should repeat (1)
Improve reluabilityEliminate human errors
Why farmers use ammonium compounds (1)
Fertiliser
Why high temp used (1)
Increase RoR
Acid used to make ammonium sulphate
Sulphuric acid
Why sodium chloride solution conduct electricity (1)
Ions free
Why chloride ions attracted to positive electrode (1)
Negative
2 possible causes of anomaly (2)
Gas escapeWeighing errorChange in tempTiming error
How student can check reliability (1)
RepeatCompare with others
How increase in con affect volume of gas produced (1)
Increases
How Fe turn into Fe3+ (2)
Lose 3 electrons
Magnesium sulfate from what acid (1)
Sulphuric acid
Why catalysts used
Speed up reaction
Why catalyst not need to be replaced (1)
Catalyst not used up
Why different catalyst used inA and B (1)
Diff reaction require diff catalysts
Why nanosized catalyst particle reduce cost of catalytic converter (3)
Smaller atomsBigger SALess catalyst needed
Why silicon dioxide suitable for welding blamkets (3)
Giant structureStrong covalent bond difficult to breakLot of energy needed to breakHigh mp
Why yield not max (1)
Reversible reactionImpure reactants
Describe effect that increasing con has on RoR (3)
RoR increasesBecause more particles/unit volumeIncrease frequency of collisions
Why hydrogen ions move to negative electrode (1)
They are positively charged
How does hydrogen ion change into atom (1)
Gains an electron
Which ion makes waste alkaline (1)
Hydroxide
Ionic equation for neutralisation (1)
H+ + OH- turn into H2O
Why reaction mixture heated (1)
Increase RoR
Mass less than calculated (1)
Weighing errorLeft in apparatus
Why catalyst work long time before need replacing (1)
Not used up
Why thermosoftening polymer not suitable for hot packaging (2)
Has low mpWeak intermolecular forces
Why solution goes cloudy (2)
Sulphur formsWhich is a solid
How gas chromatography can separate substances in a mixture of compounds (3)
Substance carried by gasThrough columnAt diff speeds
What info does molecular ion peak give about the molecule (1)
Relative molecular mass
Why scientists cannot answer question (2)
Cannot be determined by experimentBased on opinion
What happens when sodium atoms react with iodine atoms to produce sodium iodide (3)
Sodium atom loses one electron and iodine atom gains an electronForms ionic bonds
Why solution can conduct electricity (1)
Ions can move
What is formed at negative electrode when sodium iodide solutuon electrolysed why (2)
HydrogenSodium more reactive
Why electrode dry faster if use propanone instead of water (1)
Has low bp
Why results not as expected (2)
Weighing errorImpurities in electrodeLost during washing
How electrolysis used to make pure copper from impure (4)
Impure is positivePure negativeCopper loses electrons Form positive ionsGains electrons at negative electrodeAttracts at negative electrodeSludge at bottomImpurities not attracted to electrode
Copper oxide reacts faster at higher tenp why (2)
Particles have more energyMove fasterCollide more often
Why silicon dioxide used to make bricks for high temp furnaces (4)
High mpEach silicon atom joined to 4 oxygen atomsStrong covalent bondsMany needed to be brokenLots of energy needed to break bondsGiant covalent structureNo free electronsPoor conductor of heat
Why pH increased (1)
Sodium hydroxide is alkali
Why nanoparticles pass though skin easier (2)
Nano are smallerSo easily pass through skin
Why suncream containing nano should be tested further (1)
May be toxic
Why companies don’t want to test sun cream (2)
Testing expensiveTime consuming
Why metals good conductors of electricity (2)
Electrons can move aroundAnd carry charge
Why higher atom economy advantage (2)
Less wasteLess pollutionLess purificationMore useful use of atoms
Why copper good conductor of electrici (2)
Has delocalised electronsCan move through metal
How fluorine atom change to ion F- (2)
An electronIs gained
How graph support conclusion (1)
Straight lineAs con increase rate increase
Why RoR increase when con increased (2)
More particles in volume of solutionGreater frequency of collisions
What ions make solution acidic (1)
Hydrogen
What substance added to give OH-ions (1)
Alkali
Precipitate (1)
Insoluble substance
How separate precipitate from solution (1)
Filtration
Why lower temp not used (1)
Rate too slow
Acid reacts with ammonium nitrate (1)
Nitric
Why graphite has these properties (5)
Each carbon forms 3 bondsIn layersWeak intermolecular forces between layersLayers can slide over each otherOne electron not used up in bondingDelocalisedCarry chargeGiant covalent structureLots of energy needed to break bonds
Why hydrogen ions attracted to negative electrode (1)
Positive
Why hydrogen formed not potassium
Potassium more reactive
Why hydrogen in lithium nitride safer than hydrogen
H2 bonded with lithium nitrideDoes not leak
How nano different from normal (1)
Snaller
Why nano release hydrogen more quickly than normal (1)
Greater Sa
Oxidation
Loss of electron
Why companies test perfume (1)
Check safety
Were test valid or reliable (2)
Not repeatNot reliable
Why iron used (1)
Speed up reaction
How ammonia separated from nitrogen and hydrogen (2)
CooledCondensesN h not condense
Why results prove strontium chloride and barium chloride must be diff (1)
One was exo one endo
Why strontium ions attracted to negative electrode (1)
Positively charged
What property of diamond makes it suitable for use on the cutting end of a drill bit (1)
Hard
Why diamond hard (3)
Giant covalent structureStrong covalent bondsCarbon bonded to 4 other atoms
Why graphite good conductor of electricity but not diamond (3)
Graphite has delocalised electronsEach carbon joined to 3 other atomsDiamond no free electronsAll electrons used for bonding
Why sodium oxide and potassium oxide dangerous in contact with skin (1)
CorrosiveDamages cells
Scientists developed catalysts allow reaction faster at lower temp. How good for environment and manufacturer (2)
Less fuel neededConserve resourcesMore product obtained in shorter time
*Why lid on container (1)
Prevent evaporation of solvent
*Why start line drawn in pencil not ink (1)
Ink dissolves in solvent
*2 advantages of gas chromatography compared with paper (2)
QuickAccurateSensitive
*What does gas chromatography do to mixture of solvents (1)
Separates
*What info does mass spectroscopy give (1)
Identifies solvent
*Exothermic (1)
Gives out energy
*How Au become Au3+ (2)
Loses 3 electrons
*Why Co2 has low bp (3)
Small moleculeWeak intermolecular forcesSmall amount of energy needed to separate molecules
*Why gold still used as catalyst (3)
Gold only catalyst for some reactions Not used upOnly small quantities neededIncrease RoR
*Why electrolyte contain cryolite (2)
Lowers mo of aluminium oxideLess energy needed to melt it
*Why positive electrode used up (2)
Electrode reacts with O2 To form Co2
*Why 2 hydroxide ions for each calcium ion (1)
Calcium is +2 and hydroxide is -1
*Nanoparticles (1)
Particles of sze 1-100nm
*Why graphite softer than diamond (4)
Layers on graphite can slideOnly weak intermolecular forcesEach carbon atom in diamond covalently bonded to 4 othersCarbon cannot slide
*Why graphite can conduct but not diamond
Graphite has delocalised electronsCan carry charge through the structureDiamond has no delocalised electrons
Why cake rise when baked (1)
Water produced
Do reactants need to be heated (1)
Yes to start reaction
2 observations student could make (2)
FizzingChange in pHMagnesium dissolved
Why yield less than expected (1)
Reversible
What ion make ammonia solution alkaline (1)
Hydroxide
Reaction between aqueous ammonia solution and acid (1)
Neutralisation
Ammonium sulfate formula (1)
(NH4)2SO4
Why electrolysis not work on solid (2)
Charge couldn’t flowIons not free to move
How potassium atoms formed from ions (2)
GainOne electron
Purpose of gas chromatography (1)
Separate
What info do molecular ion peak from mass spectrometer give about the substances (1)
Relative molecular mass
Ion which makes sulfuric acid acidic (1)
Hydrogen
Start line drawn with ruler and ….. Why (2)
PencilInk would dissolve
Why diff compounds separate in gas chromatography column (1(
Diff substances travel at diff speedsHave diff retention times
Why chlorine is gas at room temp but sodium chloride is solid (6)
ChlorineCovalent bondsSimple moleculesWeak intermolecular forcesLow bpSodiumStrong electrostatic forces of attractionIn all directionsBetween opp charged ionsGiant latticeLarge amount of energy needed to breakHigh mp
Effect of increasing pressure on RoR (3)
Rate increasesMore particles in same volumeFrequency of collisions increase
Why b more effective ;2(
Greater SaSo reaction faster
Activation energy (1)
Minimum amount of energy needed to start a reaction
Why potassium to suitable to react with acid (2)
Too reactiveSo dangerous
How increase RoR (1)
Increase con of acidTempSA of zinc
Why zinc chloride must be molten (1)
Ions can move and carry charge
Zinc chloride what happens at negative electrode (3)
Zinc ion gain2 electronsZinc formed
How tell that reaction done at high temp (1)
Magnesium is gas
Endothermic (1)
Takes in energy from surroundings
Why carbon nanotubes used a slubricants (2)
Nano can slide over each otherWeak intermolecular forces
Why graphite conduct electricity (2)
Delocalised electronsMove through graphite
What happens when magnesium atoms react with oxygen to produce magnesium oxide (4)
Magnesium lose 2 electronsOxygen gainGive full outer shell
Glass melts at lower temp why (1)
Weaker bonds
Sodium oxide formula (1)
Na2O
Describe structure of metal (3)
LayersPositive ionsWith sea of delocalised electrons
