C2 Flashcards
(160 cards)
1
Q
Why metals can be bent and hammered into different shapes (1)
A
Made of layers which can slide over each other
2
Q
Electrolysis (2)
A
Electricity Passed through ionic substances
3
Q
Sodium chloride negative electrode
A
Hydrogen
4
Q
Why graphite conducts electricity (2)
A
1 electron from each atomIs delocalised
5
Q
Exothermic (1)
A
Gives out heat
6
Q
How ions are held together in solid magnesium oxide
A
Opp charged ionsAttract
7
Q
Hydrochloric acid + magnesium oxide turns into ? + water (1)
A
Magnesium chloride
8
Q
Soluble compound contain bromide ionsDitto silver ions (2)
A
Sodium bromideSilver nitrate
9
Q
Why lights turned out (1)
A
Silver ions reduced to silver
10
Q
Type of chemical reaction when compounds mixed (1)
A
Precipitation
11
Q
Reduction (2)
A
Electrons gained
12
Q
How decrease in temp affect yield of ammonia (2)
A
DecreaseRate of reaction slower
13
Q
Increase in pressure affect ammonia yield (2)
A
IncreaseIncrease RoR
14
Q
Economic safety and environmental factors when ammonia factory near town (3)
A
EconomicLarge town provides work forceWorkers not travel far to workSafetyEscape of dangerous gasesDanger of increased trafficEnvironmentalEye sireLoss of habitants
15
Q
How nucleus of oxygen 18 diff from 16 (2)
A
2More neutrons
16
Q
How did wohler prove that a life force is not needed to make organic compounds (1)
A
He made organic compounds
17
Q
Why most scientists still believed life force needed to produce organic compound (1)
A
Wohler lack of status
18
Q
Why most scientists believe wohler (1)
A
Wohler had more evidence
19
Q
Lead an what makes lead nitrate (1)
A
Nitric acid
20
Q
How solid lead nitrate obtained from lead nitrate solution (1)
A
Evaporate
21
Q
Exothermic. How temp will change as reaction occurs (1)
A
Increases
22
Q
Why giant covalent structures have high melting points (2)
A
Strong bondsLot of energy needed to break them
23
Q
Why increasing temp increases RoR (2)
A
Particles have more energyMove fasterCollide more often
24
Q
Nanosize (1)
A
1-100nm
25
Why nanocoated tennis balls good for environment (2)
Less need to be madeLast longerLess wasteLess pollution
26
How vapour pressure of propane changes with temp (2)
No change initiallyIncreaseSlowly at first then more rapidly
27
Why propane low bp(2)
WeakIntermolecular forces
28
How metals conduct electricity (2)
Electrons free to moveAnd carry charge
29
Why gel contain ions can conduct electricity (1)
Ions are charged
30
Why did the mass of the flask and contents decrease with time (1)
Loss of CO2
31
Why not get max amount of aspirin (1)
Errors in weighingImpure reactants
32
How catalyst reduce cost (1)
Use lower tempUse less fuel
33
Alkali formed in electrolysis of sodium chloride solution (1)
Sodium hydroxide
34
.....Cl- turn into Cl2 ............. (1)
2 +2e-
35
How sodium atom change into ion (2)
1 electron given away
36
Why chloride ions move to positive electrode (1)
Ions are negatively charged
37
Why done by independent scientists (1)
Not biased
38
Property of hydrogen chloride allow it escape into atmosphere (1)
Gas
39
Insoluble solids separated from solution how (1)
Filtration
40
Crystals obtained from solution how (1)
Evaporation
41
Simple molecules have low bp why (2)
WeakIntermolecular forces
42
Diff between H2 atom and H1 (2)
H2 1 proton and 1 neutronH1 1 proton
43
Why copper has high mp (4)
Giant latticeStrongElectrostatic forces of attractionLots of energy needed to break the bonds
44
Why student should repeat (1)
Improve reluabilityEliminate human errors
45
Why farmers use ammonium compounds (1)
Fertiliser
46
Why high temp used (1)
Increase RoR
47
Acid used to make ammonium sulphate
Sulphuric acid
48
Why sodium chloride solution conduct electricity (1)
Ions free
49
Why chloride ions attracted to positive electrode (1)
Negative
50
2 possible causes of anomaly (2)
Gas escapeWeighing errorChange in tempTiming error
51
How student can check reliability (1)
RepeatCompare with others
52
How increase in con affect volume of gas produced (1)
Increases
53
How Fe turn into Fe3+ (2)
Lose 3 electrons
54
Magnesium sulfate from what acid (1)
Sulphuric acid
55
Why catalysts used
Speed up reaction
56
Why catalyst not need to be replaced (1)
Catalyst not used up
57
Why different catalyst used inA and B (1)
Diff reaction require diff catalysts
58
Why nanosized catalyst particle reduce cost of catalytic converter (3)
Smaller atomsBigger SALess catalyst needed
59
Why silicon dioxide suitable for welding blamkets (3)
Giant structureStrong covalent bond difficult to breakLot of energy needed to breakHigh mp
60
Why yield not max (1)
Reversible reactionImpure reactants
61
Describe effect that increasing con has on RoR (3)
RoR increasesBecause more particles/unit volumeIncrease frequency of collisions
62
Why hydrogen ions move to negative electrode (1)
They are positively charged
63
How does hydrogen ion change into atom (1)
Gains an electron
64
Which ion makes waste alkaline (1)
Hydroxide
65
Ionic equation for neutralisation (1)
H+ + OH- turn into H2O
66
Why reaction mixture heated (1)
Increase RoR
67
Mass less than calculated (1)
Weighing errorLeft in apparatus
68
Why catalyst work long time before need replacing (1)
Not used up
69
Why thermosoftening polymer not suitable for hot packaging (2)
Has low mpWeak intermolecular forces
70
Why solution goes cloudy (2)
Sulphur formsWhich is a solid
71
How gas chromatography can separate substances in a mixture of compounds (3)
Substance carried by gasThrough columnAt diff speeds
72
What info does molecular ion peak give about the molecule (1)
Relative molecular mass
73
Why scientists cannot answer question (2)
Cannot be determined by experimentBased on opinion
74
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
75
Why solution can conduct electricity (1)
Ions can move
76
What is formed at negative electrode when sodium iodide solutuon electrolysed why (2)
HydrogenSodium more reactive
77
Why electrode dry faster if use propanone instead of water (1)
Has low bp
78
Why results not as expected (2)
Weighing errorImpurities in electrodeLost during washing
79
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
80
Copper oxide reacts faster at higher tenp why (2)
Particles have more energyMove fasterCollide more often
81
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
82
Why pH increased (1)
Sodium hydroxide is alkali
83
Why nanoparticles pass though skin easier (2)
Nano are smallerSo easily pass through skin
84
Why suncream containing nano should be tested further (1)
May be toxic
85
Why companies don't want to test sun cream (2)
Testing expensiveTime consuming
86
Why metals good conductors of electricity (2)
Electrons can move aroundAnd carry charge
87
Why higher atom economy advantage (2)
Less wasteLess pollutionLess purificationMore useful use of atoms
88
Why copper good conductor of electrici (2)
Has delocalised electronsCan move through metal
89
How fluorine atom change to ion F- (2)
An electronIs gained
90
How graph support conclusion (1)
Straight lineAs con increase rate increase
91
Why RoR increase when con increased (2)
More particles in volume of solutionGreater frequency of collisions
92
What ions make solution acidic (1)
Hydrogen
93
What substance added to give OH-ions (1)
Alkali
94
Precipitate (1)
Insoluble substance
95
How separate precipitate from solution (1)
Filtration
96
Why lower temp not used (1)
Rate too slow
97
Acid reacts with ammonium nitrate (1)
Nitric
98
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
99
Why hydrogen ions attracted to negative electrode (1)
Positive
100
Why hydrogen formed not potassium
Potassium more reactive
101
Why hydrogen in lithium nitride safer than hydrogen
H2 bonded with lithium nitrideDoes not leak
102
How nano different from normal (1)
Snaller
103
Why nano release hydrogen more quickly than normal (1)
Greater Sa
104
Oxidation
Loss of electron
105
Why companies test perfume (1)
Check safety
106
Were test valid or reliable (2)
Not repeatNot reliable
107
Why iron used (1)
Speed up reaction
108
How ammonia separated from nitrogen and hydrogen (2)
CooledCondensesN h not condense
109
Why results prove strontium chloride and barium chloride must be diff (1)
One was exo one endo
110
Why strontium ions attracted to negative electrode (1)
Positively charged
111
What property of diamond makes it suitable for use on the cutting end of a drill bit (1)
Hard
112
Why diamond hard (3)
Giant covalent structureStrong covalent bondsCarbon bonded to 4 other atoms
113
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
114
Why sodium oxide and potassium oxide dangerous in contact with skin (1)
CorrosiveDamages cells
115
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
116
*Why lid on container (1)
Prevent evaporation of solvent
117
*Why start line drawn in pencil not ink (1)
Ink dissolves in solvent
118
*2 advantages of gas chromatography compared with paper (2)
QuickAccurateSensitive
119
*What does gas chromatography do to mixture of solvents (1)
Separates
120
*What info does mass spectroscopy give (1)
Identifies solvent
121
*Exothermic (1)
Gives out energy
122
*How Au become Au3+ (2)
Loses 3 electrons
123
*Why Co2 has low bp (3)
Small moleculeWeak intermolecular forcesSmall amount of energy needed to separate molecules
124
*Why gold still used as catalyst (3)
Gold only catalyst for some reactions Not used upOnly small quantities neededIncrease RoR
125
*Why electrolyte contain cryolite (2)
Lowers mo of aluminium oxideLess energy needed to melt it
126
*Why positive electrode used up (2)
Electrode reacts with O2 To form Co2
127
*Why 2 hydroxide ions for each calcium ion (1)
Calcium is +2 and hydroxide is -1
128
*Nanoparticles (1)
Particles of sze 1-100nm
129
*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
130
*Why graphite can conduct but not diamond
Graphite has delocalised electronsCan carry charge through the structureDiamond has no delocalised electrons
131
Why cake rise when baked (1)
Water produced
132
Do reactants need to be heated (1)
Yes to start reaction
133
2 observations student could make (2)
FizzingChange in pHMagnesium dissolved
134
Why yield less than expected (1)
Reversible
135
What ion make ammonia solution alkaline (1)
Hydroxide
136
Reaction between aqueous ammonia solution and acid (1)
Neutralisation
137
Ammonium sulfate formula (1)
(NH4)2SO4
138
Why electrolysis not work on solid (2)
Charge couldn't flowIons not free to move
139
How potassium atoms formed from ions (2)
GainOne electron
140
Purpose of gas chromatography (1)
Separate
141
What info do molecular ion peak from mass spectrometer give about the substances (1)
Relative molecular mass
142
Ion which makes sulfuric acid acidic (1)
Hydrogen
143
Start line drawn with ruler and ..... Why (2)
PencilInk would dissolve
144
Why diff compounds separate in gas chromatography column (1(
Diff substances travel at diff speedsHave diff retention times
145
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
146
Effect of increasing pressure on RoR (3)
Rate increasesMore particles in same volumeFrequency of collisions increase
147
Why b more effective ;2(
Greater SaSo reaction faster
148
Activation energy (1)
Minimum amount of energy needed to start a reaction
149
Why potassium to suitable to react with acid (2)
Too reactiveSo dangerous
150
How increase RoR (1)
Increase con of acidTempSA of zinc
151
Why zinc chloride must be molten (1)
Ions can move and carry charge
152
Zinc chloride what happens at negative electrode (3)
Zinc ion gain2 electronsZinc formed
153
How tell that reaction done at high temp (1)
Magnesium is gas
154
Endothermic (1)
Takes in energy from surroundings
155
Why carbon nanotubes used a slubricants (2)
Nano can slide over each otherWeak intermolecular forces
156
Why graphite conduct electricity (2)
Delocalised electronsMove through graphite
157
What happens when magnesium atoms react with oxygen to produce magnesium oxide (4)
Magnesium lose 2 electronsOxygen gainGive full outer shell
158
Glass melts at lower temp why (1)
Weaker bonds
159
Sodium oxide formula (1)
Na2O
160
Describe structure of metal (3)
LayersPositive ionsWith sea of delocalised electrons
