Flashcards
CHEM
Cards in this deck (148)
- 1What is the definition of Allotropedifferent physical forms, same element
- 2What is the definition of IsotopeSame no. of protons, different no. of neutrons
- 3Suggest a method to store lithium in school labunder paraffin oil
- 4What are the two essential condition for rustingPresence of water and oxygen
- 5What ion is responsible for appearance of pink colour in rusting ironOH ion
- 6What is the purpose of adding rust indicator into gelprovide medium for ion movement
prevent spread of colour of indicator - 7—alkene can decolorize red-brown bromine solution
- 8What apparatus is suitable to hold 25cm3 distilled watervolumetric flask
- 9Explain the formation of black smoke when candle is lightedincomplete combustion
- 10Suggest one harmful effect of black smoke/ photo-chemical smogirritates respiratory system
- 11is polythene suitable to make plastic bagnot suitable, it is hard and brittle
- 12when lithium is exposed to air, what makes the metal surface become dulllithium oxide
- 13Compare the reactivity of lithium and sodiumNa is more reactive
the outermost electron shell is further away from central atom, weaker electrostatic force - 14The reaction when sodium hydroxide is exposed to air for long time and dilute hydrochloric acid is addedNaOH absorbs CO2 to form Na2CO3
colourless gas bubble is form
the Na2CO3 react with HCl to give CO2 - 15Is fluorine or chlorine more electronegativeF is more electronegative
the electronegativity decreases down group VII - 16Compare BF3, BHF2 and BHCl2 in terms of their shape, polarity and boiling pointShape: they all possess trigonal planar
Polarity: BF3 is non-polar, the three BF bonds are equally separated due to their repel force, their polarity is cancelled out
BHF2 is more polar than BHCl2, F is more electronegative than Cl
Boiling point: BHF2 has higher boiling point, the intermolecular force is higher due to stronger polarity
BHCl2 has higher bp than BF3 because BF3 is non-polar - 17The Big equations for redoxGERC(-)
LEAO(+)
GainElectronReduceCathode
LoseElectronAnOx - 18How can chromium protect iron from rustingchromium-plating
- 19Will the rate of rusting be faster when nickel wire is added to iron wireIt would be faster, nickel is less reactive than iron
- 20What is the bond between Al ion and O atom in water[Al(H2O)6]3+
dative covalent bond - 21Draw the 3D structure of diamond, graphite and silicon dioxide
- 22What are the shapes for compoundslinear, trigonal planar, tetrahedral, trigonal pyramidal, v-shape, trigonal bipyramidal, octahedral
- 23Group VII electronegativity, boiling point orderElectronegativity: Decrease down the group
Boiling point, increase down the group, larger molecular size - 24Which is partial positive or negative charge in HClH partial positive charge, arrow towards Cl
- 25When is a compound with hydroxyl group soluble in water or organic solventInsoluble: long carbon chain, the van der waals force become dominant force, overcoming hydrogen bond
- 26Ice propertiesStructure: water molecule form hydrogen bond with four other tetrahedrally
empty space among water molecule form open structure, lower density than water
oxygen atom in hexagonal shape
Physical: when melt, open structure collapses, molecules pack closely - 27C60 propertiesStructure: simple molecular structure, spherical
carbon atom to three other
Physical properties: low melting point, van der waals force
bad electrical conductor, spherical shape hinder delocalized electron movement
non-polar - 28What dilute and concentrated solution give in redox cell, electrolysisdilute: GERC(-) OH
LEAO(+) H
concentrated: GERC(-) SO42-, Br, F, I
LEAO(+) Na
molten: compounds' ion only
all conduct electricity, except CnH2nOH - 29Color for Cu, Fe, CrO4, Ni, Cr, Cr2O7, Co, Mn, MnO4Cu (blue/ green)
Fe (green/ yellow)
CrO4 (yellow)
Ni (green)
Cr (green)
Cr2O7 (orange)
Co (pink)
Mn (pale pink)
MnO4 (purple) - 30Metallic bond propertiesfree electrons
metal ions are surrounded by 'sea of electrons'
ions can slide over others without breaking - 31Use of salt bridge1 allow ions to move from one to another half cell to complete circuit
2 balance the charge accumulated - 32Flow direction of electron in cellFrom more reactive rod to less reactive in wire circuit
Or the battery terminals, + - --> e-, that rod is (+), -ve ions are attracted to it - 33Use of porous pot in cells1 allow ions to move between solutions to complete circuit
2 prevent direct mixing of reactants - 34what are the advantages of hydrogen-oxygen fuel cell1 it has constant voltage
2 high efficiency
3 clean fuel, only product is water, non-polluting products - 35Why is mercury cathode stored in a u-shaped tubeto prevent evaporation of mercury
- 36Which are the equations of mercury cathodeCathode: Na+ + Hg -> NaHg
Anode: 2Cl- -> Cl2 + 2e- - 37What is expected observation when two rod of the cell is the same metalremain unchanged, concentration is unchanged
- 38What are the 8 factors affecting the rate of reaction1 catalyst
2 surface area
3 temperature, faster particle movement
4 reactivity, more reactive, larger distance of ecs position
5 ratio in equation
6 pressure, packed closely
7 state, liquid/ gas - 39Collision theorygases less likely to collide
right orientation
right position
enough speed for activation energy - 40How to slow down reactionQuenching/ cooling
adding ice/ water, temperature decrease, less energy for reaction
dilute
remove catalyst with reagent
neutralisation - 41What is the color change for phenolpthaleinacid to alkaline
colourless to pink - 42what is the color change for methyl orangeacid to alkaline
red to yellow - 43what is the colour change of starch/ iodinecolourless to brown
- 44How to measure change of rate of reactionvolume of gas: gas syringe
pressure of gas: pressure sensor + data logger
mass of mixture: electronic balance
H2 cannot be weighted, little weight
Color intensity: colorimeter detector with yellow filter
transmittance of light through mixture
concentration blot out cross, cloudy solution - 45How to calculate rate of blotting out of solutionRate = 1/time
- 46How do we see whether the solution is self-catalysted from the graphXXXX
- 47How to explain the S-shape of the reaction graph and what to dothe reactant is soluble, the real reaction starts when the solution is saturated
CO2, SO2 is very soluble in water
Solution: take calculation behind it
saturate the solution first - 48What are the structural isomersdifferent order of linkage
chain, position, functional - 49What are the stereoisomerscis-trans isomer/ geometrical isomer
optical/ enantiomerism - 50What does melting point and boiling point depends onBoiling point: strength of polarity
Melting poinit: packing efficiency
especially cis-trans isomer - 51optical isomer defintionnot superimposable
- 52optical isomer propertiesthey can rotate polarized light beam
polarimeter clockwise and anti-clockwise - 53What reaction may have major and minor productsAddition of HX to alkene
Dehydration con. H2SO4
substitution of alkane, chain reaction
h atom added to c atom with more h atom in major product - 54Step for substitution reaction1 X2 into free radical
2 sub X into alkane
3 form HX - 55What are the reactions of alkane, how to identifyAdd H2, X2, HX, MnO4, NaOH
decolorize red-orange bromine solution - 56Difference between addition of HX and PX3HX: sub OH with double bond destroy
PX3: sub OH without breaking d bond - 57All oxidation reactions MnO4 oxidizing properties Color change1* alcohol: aldehyde to carboxylic acid
2*: ketone
MnO4 strong oxidizing agent, direct carboxylic acid
orange Cr2O7 to green Cr3+ ion - 58MnO4, Cr2O7, Fe, Ag, Cl2 oxidizing result and color changeMnO4- -> Mn2+ purple to pale pink
(Cr2O7)2- -> Cr3+ orange to green
Fe3+ -> Fe2+ yellow to green
Ag+ -> Ag colourless to silver
Cl2 -> 2Cl- green to colourless - 59Br2, NO3, H2SO4 oxidizing result and color changeBr2 -> 2Br- red-orange to colourless
NO3- -> NO colourless
NO3 -> NO2 colourless to brown
(SO4)2- -> SO2 colourless - 60Why are acid and alkaline strong and weakstrong acid can competely ionize in water, therefore there are higher concentration of H+ ions
weak acid undergo reversible reaction, makes it partially ionize - 61What are the strong and weak acidsStrong: H2SO4 sulphuric acid, HCl hydrochloric acid, HNO3 nitric acid
Weak: CH3COOH ethanoic acid - 62what are those: critic acid, calcite, sulphurous acid, sulphites, sulfites, hydrogen sulfiteC6H807 mainly COOH
CaCO3
H2SO3
(SO3)2-
HSO3- - 63Convertion of Calcium carbonate (marble) and other namesCaCO3 heat gives out CO2 CaO quicklime
CaO add H2O give Ca(OH)2 slaked lime
excess water to limewater
limewater add CO2 to turn milky
excess CO2 to Ca(HCO3)2
evaporate gives out CO2 form CaCO3 - 64What are basesmetal oxide or hydroxide
- 65Mass Spectrometer (VIADD)Definition: machine use to ionize sth
Vaporisation - Sample is turned into a gas
Ionisation - Hit with fast moving e- to knock an e- from sample, make it +1 ion
Acceleration - +1 ion directed towards a negative magnetic field
Deflection - light fast moving e- deflected, heavy slow e- aren't deflected
Detection - Ions reach detector, each producing a current depending on the abundance - 66Lithium flame testCrimson
- 67Potassium flame testlilac
- 68sodium flame testgolden yellow
- 69calcium flame testbrick red
- 70copper flame testbluish green
- 71barium flame testgreen
- 72test for carbon dioxideturns limewater milky
- 73test for chloridepass through dilute HCl then silver nitrate test
appearance of white chloride precipitate - 74test for oxygenrelights glowing splint
- 75what are the uses of hydrogen1 margarine
2 ammonia NH3 - 76what are the uses of chlorinesterilize swimming pool water HOCl
- 77what are the uses of naoh1 make soap
2 drain cleaner - 78what are there erosion of rocks, buildingsCO2 dissolves slightly in rainwater
forming carbonic acid H2CO3 - 79CaCO3 + H2SO4CaSO4 + CO2 + H2O
- 80aldehyde/ carboxylic acid to alcoholLiAlH4 in dry ether
or NaBH4 - 81Ways to extract metal from their oxidesdisplacement, heat, strongly heat, reduction with carbon, electrolysis
- 82What metal are extracted using electrolysisK, Na, Ca, Mg, Al
- 83amide to carboxylic acid gives out?1 NaOH
2 H+ heat
1 H2O
2 H+ heat
NH4+ ion - 84What metals are extracted using carbon reductionZn, Fe, Sn, Cu
- 85what is and how to esterificationfrom carboxylic acid and alcohol
added to con. H2SO4, condensation
produce ester and water - 86what element is purified by electrolysiscopper
- 87what is the liquid used in electrolysiselectrolyte
- 88how to create diolfrom alkene, added naoh/ dilute mno4 (otherwise, its oxidiation)
- 89what is the importance of crackingproduce extra petrol since heavy fractions are less demanding
produce alkene to make organic compounds and synthetic products (addition polymer) - 90adding hexane into bromine solution, what is the expected observationbromine solution decolorize
hexane become purple (Br2 in organic solvent)
halogens tend to dissolve in organic solvent due to comparable van der waals force - 91organic compound reactions in dark roomfor hexane, UV light must be applied for energy for subsititution reaction
for hexene, no energy is needed, addition reaction - 92what will cracking producealkane and alkene
- 93what is cracking what are the two typesbreak down large molecules into smaller one heated with the presence of air
thermal cracking: heated with high temperature
catalytic cracking: Al2O3 with SiO2 in lower temperature with good quality control - 94what are the colors of I2 in aq, gas, organic and solid stateaq brown
gas/ organic purple
solid black - 95catalyst used in crackingAl2O3 + SiO2
- 96what is the safety measures in crackingprevent tube first to prevent sucking back
- 97what are saturated and unsaturated hydrocarbonsalkane and alkene
- 98what is the chem properties of alkaneunreactive with acid, alkali, oa, ra
- 99equation of alkaneCxHy + (x+y/4)O2 -> xCO2 + y/2H2O
- 100what incomplete combustion gives outcarbon monoxide CO, soot
burns with more sooty yellow flame - 101application of neutralisationadjust soil ph
neutralize excess acid stomach
treat industrial liquid waste
fertilizer NH3 - 102application of NH3fertilizer
- 103preparation of insoluble saltby precipitation
filter wash dry - 104preparation of soluble saltdissolve metal
filter
evaporation
wash, dry - 105what halide, sulphate, cabonate are not solublehalide: Ag Pb
sulphate: Pb Ba, Ca (slightly)
carbonate: K Na NH4 - 106test presence of watercobalt II chloride paper blue to pink
- 107what redissolves in naohZn Al Pb
Zn dol Al leh juo Lead - 108what redissolves in NH3Ag Cu Zn
Silver dol Copper leh juo Zn tin - 109NH4+ + NaOHpungent gas formed
which turns wet red litmus paper blue
NH3 - 110NaHCO3 + H2SO42NaHCO3 + H2SO4 -> Na2SO4 + 2CO2 + 2H2O
- 111what safety measures when doing acid and alkali reactionswear protective gloves
perform in fume cupboard to avoid acid mist
dilute concentrated stuff slowly - 112what is the use of conservation of chemicalssave energy and resources
reduce metal waste
reduce cost - 113mg flame testdazzling white
- 114what are the special color metal oxidesblack Fe
yellow Pb
black Cu
red Hg - 115observation of metal in water color change of phenolpthaleinmelt to silvery ball, burn in flame
coiourless gas bubbles
colourless to pink, turn alkaline, more MOH - 116metal with cold water vs steamcold water -> OH
steam -> oxide - 117Mg + heated steamintense white light
form white MgO - 118apparatus for metal + cold water and steaminverted funnel
delivery tube - 119the electrochemical seriesK Ca Na Mg Al Zn Fe Pb
H+ H2SO4
Cu Hg Ag Pt Au
O I Fe3+ NO3- Br (Cr2O7)2- Cl MnO4- - 120what are the secondary cells and their electrolyteNickel-Cd (KOH), Lithium ion, Lead acid accumulator (H2SO4)
- 121what are the primary cellsZn Carbon (NH4Cl), alkaline manganese (KOH), silver oxide (KOH)
- 122what are the advantages of electroplatingprevent metal from rusting
improve corrosion- resistance - 123what are the difference between chemical cell and electrolyte cellchemical cell: more reactive to less reactive in external circuit
electrolyte cell: electrolysis using electrical energy to move ions to rods
chemical cell: produce electricity - 124how to treat chromium wastereduce them to Cr3+ and hydroxide them
- 125what is the use of anodizationenhance appearance with dying
improve corrosion resistance - 126what affects the preferential discharge of ionsrod positions in ecs
concentration of solution (con. give actual ions) - 127how to calculate enthalpy changeheat released /no. of mole
- 128neutralization calculation errorsdensity and specific heat capacity of reaction mixture is not the same of water
- 129why cant we directly do the enthalpy reactionthere are side reactions
formation are highly exothermic
elements are in different physical state - 130how to calculate enthalpy change in the cycle^Hc put on left
^Hf put on right - 131what is similar and trend in homologues seriessame general formula
similar chemical properties
down the series, molecular size increases, van der waals force increases, mp bp density increases - 132why are alkane insoluble in water1 not comparable in intermolecular force
2 less dense than water - 133equation of molemole = m/rmm
mole = particle/ NA - 134measuring pHuniversal indicator, pH meter, paper, sensor with data logger (pressure sensor)
- 135how to make a substance dissolve then make up to 100cm3wash volumetric flask with distilled water
add substance and add distilled water until it reach graduation mark - 1368 fractional distillation of petroleum and their usesrefinery gas/ LPG: taxi
petrol/ gasoline: motor vehicles
naptha: town gas
kerosene: airplane
diesel oil: heavy vehicles
fuel oil: ships
lubricating oil and waxes: candles
bitumen: roads - 137water pollution from oil spilagefloat on water block oxygen supply
poisonous
flammable - 138medical application of aspirin and side effectsreduce pain, heart attack
increase bleeding - 139difference between soapy detergents and soapless detergentsSoapy: made from fats or oils
ionic head: COO-
Soapless: hydrocarbon derived from petroleum
Ionic head: O/ benzene SO3- - 140hydrocarbon tail and ionic headionic head: hydrophilic
hydrocarbon tail: hydrophobic - 141detergent properitieswetting: reduce surface tension of water
emulsifying: negatively charged oil droplet repel each other - 142difference between nylon and polyesterNylon: COOH and NH2 amide linkage
CONH2
Polyester: COOH and OH ester linkage
COOC
Nylon: fishing line, tennis racket
Polyester: food container, drink bottle - 143alcohol to chloromethaneseparating funnel add HCl
drop bottom aqueous layer
add nahco3 to remove excess acid
add anhydrous sodium sulphate to absorb water
filter, distillation - 144test for sulphateadd dilute HCl and BaCl
BaSO4 white precipitate will form - 145test for nitrateadd NaOH and Aluminium powder and heat strongly
NO3- + NaOH -> NH3 + Al(OH)4
NH3 will form, turning red litmus paper blue - 146test for carbonateCO3 -> CO2
turns limewater milky - 147test for brominepass through dilute HCl then silver nitrate test
appearance of cream chloride precipitate - 148test for iodide ions (I-)pass through dilute HCl then silver nitrate test
appearance of yellow chloride precipitate
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- Flashcards on CHEM, created by Games Technology Power on 20/06/2018.
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- Created by YoGurd NoLife · Jun 14, 2018
- Copied by Games Technology Power · Jun 20, 2018
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