Oxidising agentsHydrogen peroxidePotassium manganate(Vii)Potassium dichromate(VI)(orange,turns green,K2Cr2O7 to Cr3+)CrO4 yellow>orangeConc.Nitric acid&warm(NO2 forms)NaClO,&similar

Reducing AgentsSodium sulphideZincwarmAlLiH4Conc.H2SO4

Dehydrating AgentsAl2O3 at 400C,H2SO4,Conc.Phosphoric acid,Calcium oxide,Anhyd Na2SO4

 

flame-LI RED RU RED CS SKY BLUE NA BRIGHT YELLOW K PALE LILAC CA BRICK RED ST BLUISH RED BA APPLE GREEN CU BLUE CE+MG ORANGE

 

 

Fe(OH)2 - pale green,   Fe(OH)3 - dark brown

Testing  Fe3++CNS--->Fe(CNS)2+(deep red),blue colour with hexacyanoferrate with Fe2+

Mohr salt -(NH4)SO4.FeSO4.6H2O,Iron alum -(NH4)2SO4.Fe2(SO4)3.24H2O

 

Extracting limonene- use steam distillation&fresh outer bits of orange

 

Alcohols

Mix with H2O,up to C5,pH7.Ethanediol + triol are antifreezes

Esterification + substitution to form hallogenoalkane - occurs in acid conditions(sulphuric)

PCl5 reacts to produce POCl3+HCl

Phenol is antiseptic

Oxidation turns them to ketones/aldehydes/no for tertiary.Aldehydes will oxidise further if product is not removed

If acid is in excess alkene is formed,if alcohol is in excess ether is formed

Getting Cyclohexene from cyclohexanol

Mix hexanol&phosphoric acid&distil slowly with antibumping granules between 70-90C

Evidence for ions - electrical conductivity,solutions arrange in charge,regular shapes of crystals

Alcohol can be determined by excess acidified sodium dicromate(VI)and H2SO4(ethene)(others wont react)

 

 Laboratory preparation

1Equation + amounts of reactants to use

2Measuring

3Mixing using suitable apparatus,keep in right conditions long enough(heating or catalyst)

4Separate product from the mixture

5Purify

6Weight&calculate yield

7Test that process produced right thing

 

 Halogens

Fluorine electrolysis of KF in anhydrous HF(fluorite,CaF2)

Chlorine electrolysis of saturated NaCl(aq)(rock salt,sea)

Bromine oxidation by Cl(sea)

Iodine reduction of iodate by NaHSO3(caliche containing NaIO3)soluble in HC solvent

2I-+ClO-+H2O>I2+Cl-+2OH,but goes colourless coz I2 reacts with OH

4Br2+Na2S2O3+5H2O>Na2SO4+H2SO4+HBr

Cl reacts with HBr etc.Add organic solvent to dissolve Hal2 molecules forming(colour)

Cl2+2NaOH-->NaCl+NaClO+H2O(cold sodium hydroxide)(ClO decomposes in heat & sun)

3l2+6NaOH-->5NaCl+NaClO3+3H2O(hot hydroxide)- disproportination

KIO3 is insoluble in cold H2O,IO3- reacts with 5I- to produce 3I2,that reacts with thiosulphate(ind.starch)to form Na2S4O6

Down the group ease of oxidation of Hal- increased,HalO3- decomposing temp.decreases

Oxidising ability KOCl<KClO3,but HOCl>HClO3!

AlCl3+H2O>AlOH3 first in period that hydrolyses

I->I2 in our bodies importance Cl>I>F>Br

tertiary iodoalkane least stableCH2=CH2+Br2+NO3- polarised Br

Chain initiation propagation termination molecules produced every cycle

BrCH3+heat ethanolic NH3,pressure>H2NCH3,nucleophilic

KOH+CaOH eliminates HCl

White AgCl reacts with ammonia & light,cream AgBr reacts with conc.(not dil.)ammonia + light,yellow AgI doesn't react with any

Conc.H2SO4(-->SO2),HF(g),HCl(g),HBr+ little Br2,little HI +I2(g)

conc.H3PO4,HF(g),HCL(g),HBr(g),HI(g)

conc.H2SO4+MnO2,HF,Cl2(g),remove HCl + dry,Br2(g),I2(g)

 

Chemisorption - actual bond between catalyst&gas,physical adsorption - only WdV forces

 

Standard enthalpy change of formation-M(standard state)-->M+(aq)

Hydration energy-Gas dissolves in H2O

Enthalpy-LiCl -400 NaCl -410 Na2O -414 MgO -600 HCl -90 HI +26

Lattice NaCl -780 NaI -705 KCl -711 AgCl -905(differs with theory)

Distortion more by high charge density & large(or double)negative

Measure-temperature or electrical compensation.Determine soln conc.Measure volumes.Thermometer 0-100 at 0.1C.Stir well.Include a sample calculation

dHsolution=NaCl+aq->Na+aq+Cl-aq,more charge density more exothermic

Solid - vibrational energy,gases also a rotational energy

 

1st law of thermodynamics- energy is always conserved,2nd-spontaneous reactions go towards increasing entropy,3rd - all perfect crystals have entropy of 0

Entropy for gases are for 1/2(G2)and is given in Jmol-1K-1.Always add table of values

Kc will not include solid/liquid.Kw=55.5Kc=10-14mol2dm-6

 

pH=pK-log{eq \f(HIn,In-)},at midpoint pH=pK

Ka dissociation constant of acid =H+A-/HA(constant)

Standard entropy assumes no mixing of reactants,in reality if they mix entropy is increased up to a point - dynamic equilibria.dStot=8.31LnKc.+40 -40-mixture,+200 -200 complete

Higher temperatures lower entropy change with system + rate of exothermic reactions.Pressure is decreased - > entropy of a gas is decreased

Le Chatelier - when eq is subjected to a change,the processes that take place will counteract the change.(lower pressure when there are more reactant molecules)

Lothar Meyer-volume,Lavoiser-elements that cant be decomposed

Ethanoyl chloride,made by PCl5.Nucleophilic substitution with alcohol,acylation

Esterification is reversible with dilute acid or alkali(better)

MNO4 in alkali oxidises hexanone in ring-opening reaction

 

Acid anhydrid+NH3>ammonium ethanoate

Acyl chloride+NH3>ethanamide

Amines form complexes only if they have N-H

N distinguished by adding NaOH-salts give of ammonia in cold,amides when warmed&amines don't react

Amides+phenol go to esters slowly with OH-

Phenol pH-6(No CO2)

Esters are reduced by LiAlH4 to alcohols

Br2 + phenol > 2,4-bromophenol,Br2 not with others

Sodium carbonate will not react with alcohol,but will with others(delocalised phenol dissolves)

Phenol will not readily react with HBr,but alcohol will

<>+HONO2-H2SO4,50C-> <>-NO2 yellow oil->reduction to aniline

Phenol only reacts with H2,under several hours reflux(or fuming with SO3)with H2SO4

<>+Cl2 with AlCl3 or BrCl -> <>-Cl +HCl

<>+OH-,pressure->phenol

<> + Cl2-uv->cyclochlorohexane,whereas <>-CH3 + Cl2-uv-><>-CH2Cl

<>-CH3+MnO42--><>-COOH

2HObenzoic acid + anhydride(excess)-85% H3PO4(friendly,cheap)->aspirin+acid.Hydrolyse excess anhydride,cool in H2O,suction filtration.Add OH- +citric acid for soluble aspirin

2HObenzoicacid+methanol-conc.H2SO4,reflux an hour->oil of wintergreen(3HC2OC-<>-OH)+H2O.Cool,filtrate into separating funnel with cold H2O,solvent extract by washing with organic solvent,mix,separate,wash organic layer with KHCO3 releasing pressure,dry with anhydrous sodium sulphate&distillate

dimethylamine is strong base.Amines are soluble in H2O.Electrophilic substitution.add acyl chloride to produce amide.Amine has fish-smell add acid smell disappear

2aminobenzoic acid,add excess anhydride&reflux quarter of an hour,add H2O&cool slowly to form 2-ethanoylaminobenzoic acid H2OC-<>-NHCOCH3,triboluminescene - rubbing crystals produces light

 

cathode-,cathion+,anode+,anion-

energy exchanged=spec.heat capa(4.18)xsolution mass(same as H2O)xdtemp

Intensive properties do not vary with amount(colour)and are same in equilibrium.Extensive properties(mass)vary

Strong acid-weak base - methyl orange red>yellow

Weak acid-strong base - phenolphtalein colourless>red

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{info author|Keith Siilats}, {DATE|22/01/96}, Subject: {info subject|Chemistry}, Words: {info numwords|600}

 

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