Any paper 6 doubts , tips , "helps" , questions be put here
goodluck to all >.<
Please critisize the information. and help increase it
ILL UPDATE WHEN I CAN :-*
SOLUBLE COMPOUNDS INSOLUBLE COMPOUNDS
ALL Na, Potassium , Ammonium salts -
All Nitrates ( Best for electrollytes ) ;) -
All Sulfates Except Barium Lead nd Calcium ( L , B , C) <--good way to learn
Na,potassium , ammonium Carbonates All other carbonates
All Halides Except Silver & Lead ( the anions test remember )??
All hydroxides except those of Group I, Strontium, Calcium and Barium
All ethanoates
(thanks jdarren :)), thanks 6394 :)
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OXIDISING AGENSTS : KMn04 (V11) FROM PURPLE TO COLOURLESS / K2Cr2O7 (V1) FROM ORANGE 2 GREEN / HALIDES
REDUCING AGENTS : ALL METALS ..
Dehydrating Agents : Sulfuring Acid Drying agent : Calcium Oxide
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CHEMICAL
TEST FOR WATER:1. COBALT (11) CHLORIDE BLUE TOPINK
2. WHITE ANHYDROUS COPPER (11) SULFATE TO BLUE becomes hydrated
PHYSICAL
B.P AND M.P SHOULD MELT AT FIXED POINTS! NOT RANGE !!
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CHROMATOGRAPHY
By Chromatography. Draw datum line 2cm from bottom of chromatography paper in pencil ( isnoluble , so does not affect results ).Pipette a concentrated spot of dye on the line. suspend paper in in solvent so as the solvent level is below the datum line. Wait for solvent to reach till end of the paper. Now..depending upon the question you say..:
1.Check for different dyes because there are diffrent spots.
2.Spray locating agent if there is amino acids or simple sugars ( products of hydrolisis )...cz they are colourless (thanks sarasa)
3.identify by RF values : dist. moved by dye/dist moved by solvent.
Chromatography is used to identify and seperate a MIXTURE of subtances according to their different solubilties in water and their attraction to the chromatography paper
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DO NOT FORGET DAMP LITMUS PAPER !!!!
test of oxygen : GLOWING SPLINT : RELIGHTS! [HYDROGEN PEROXIDE + MANGANESE 4 OXIDE ]
test 4 hydrogeb :LIGHTED SPLINT : SQUEAKY POOOP![ HCL + MG RIBBON ]
test 4 ammonia (aq) : turns red litmus paper blue [AMMONIUM CHLORIDE + NAOH]
test 4 chlorine : turn litmus paper red then bleeches it[KMnO4 + HCL ]
test 4 carbon dioxide : buble thro limewater..turns from colourless to milky white [CALCIUM CARBONATE + HCL ]
----------------------------------------------------------------------------------------------------------------------- INDICATORS
ACID ALAKLINE SOLT.
Phenolpthalein : colourless Pink
Methy orange : rred yellow
Methyl red : red yellow
limus : red bluw
pH scale: jst gets the no.
UNIVERSAL INDICATOR
STRONG ACID WEAK ACID NEUTRAL WEAK ALKALINE STRONG ALKALI
0,1,2 3, 4 , 5 , 6 7 8, 9 10 ,11 12, 13 , 14
RED ORANGE YELLOW GREEN BLUE PURPLE
Why is it better to use litmus paper than univ ind. solution. in a coloured dirink to check pH?
CZ COLOUR CAN ALTER the colour of indic
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Appearance of stuff
TRANSITION METALS : COLOURED METALS . AAAAALLL COLLOURED SALTS !!!!!!!!!!!!! FAMOUS OONES :
1.Copper salts ( blue ) .except copper (11) oxide = black . copper (111) carbonate = green
2. iron fe (2+) DIRTY ::) green ( 3+) brown ..... altho remember rust orange flaky hydrate [fe (3).Xh20] is orange!
GROUP 1+ 2 : SILVEEEEEEEEEEER GREY !!/ DULL GREY WHEN CUT!!!!!!!!!!!!!!!! WHITE SALTS!!!!!!!!
AMMONIUM SALTS ARE WHITE :o
Halides REMEMBER THEY ARE ALL COLOURLESS IN THEIR (Aq) FORM ..FOR EXAMPLE KI , KBR..
Flourine Pale yellow (g) colourless in soltn im nto sure ..
Chlorine pale green (g) colourless in soltnim not sure..
Bromine brown volatile (g) ornage brown soltn. when displaced form solution..
Iodine purple blck (s) forms dark brown or purple soltn. when displaced from solution
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PREPARATION OF SALTS
1.TITRATION METHOD.2.EXCESS REACTIVE METAL 3. EXCESS WEAK INSOL METHOD . 4PRECIPTATION
HEAT : NO / NO / YES +STIR / NOP
RCTN. : NEURALISATION/ REDOX / NEURTALISATION / DOUBLE DCOMPOSITION
Titration method : --used also to chck monoprotic and diprotic--
USED ONLY WHEN MAKING A SOLUBLE SALT !!!!!
Apparatus : Pippete ( Measure fixed vol. of liquid 25.0 /50.0 )
Burette ( Measure any vol. up to 2 decimal places ! ..0.00-50.00)
Any indicator ( usualy phenolpthalein or methyl red )
Conical flask
What happens? ( DO NOT FORGET TO MENTION NUMBERS USED OR AQUOS OR SOLID OR HOW MANY GRAMS ETC !!!!!!!)
- In titration we are trying 2 find EXACT volumes of acids used to neutralise and alkali or vice versa ! so.. PREPARATION OF NACL using titration.!!
Pippete 25.0cm of HCL into a conical flask
Add 3 drops of Phiphi. (colurless in acid.)
Add Na0H drop-wise from burette until colour just turn from colourless to pink in the conical flask
Measure how much Na0H was used from burette.
Repeat experiment wihtout without Phiphi and use a little less NaoH from burette..NOW WE HAVE A 100 % PURE SOLUBE SALT soltn..
then do the evaporation stuff for pure crystals etc..
Excess Relative Reactive metail (( DO NOT FORGET TO MENTION NUMBERS USED OR AQUOS OR SOLID OR HOW MANY GRAMS ETC !!!!!!!)
Always we use a metal that is STRONGER than HYDRGEN as we use it to displace Hydrogen from 25cm3 of HCL / H2SO4
What happens?
We add EXCESS of metal to H2SO4 ( 25cm3
Wait until effervecence of colourless gas stops and solid stops decreasing in size...( means all sulfuric acid is used up..!producing a SALT SOLUTION )
Filter to seperate excess metal from soluble..
..then do crystallisation stuff and etc..
Excess insoluble metal oxide *insoluble .so it does not affect the salt formed ! * does not make it alkaline.
Like copper for exacmple...weaker than hydrogen.. so we have 2 choices..Either use copper oxide or copper carbonate
but we only use heeat for copper oxide..
what happens?
Same process as a more rective metal but just with alot of heat and stirring !!!!!!!!!!!!!!!
then.. filter etc..
PRECIPITATION
Mixing two solube salt solutions to form an insoluble salt!!!!!!!!!!! Example ( 2g KI and 2g Lead Iodide )
What happenS?
Pour excess water into each beaker containing soluble saltes. Stir to dissolve to obtain 2 solution.
Now MIX . and obtain precipitate..wash ppt. with minimal amounts of dstilled water to remove traces of lead nitrate!
now dry the ppt in desiccator
CRYSTALLISATION ( REMEMBER NEVER USE EVAPORATING WITH HYDRATED SALTS ) theyll lose water and diieeee
EVAP UNTIL CRYST. POINT
COOL TO CRYSTALLSE
FILTER AND WASH WITH MINIMAL AMOUNTS OF COLD DISTILLED WATER TO OBTAIN PURE CRYSTALLS
LEAVE IN DESICCATOR OR BETWEEN 2 WADS OF FILTER PAPER
Saturated solution : soltn which contains max. amount of solute tht can be dissolved in a solvent at a part. temperature
How to make a sat solution?? ( nacl)
Place 25cm3 of distiled water in a beaker and heat GENTLY. Add excess of NACL 1 spatuala at a time utnil no more can dissolve
put a water bath on beaker to prevent anything to enter. cool to crystallise .filter. and u have a sat solution at room temp !
MAZIT ..MG, AL , ZN, IRON , TIN , REACT WITH ACIDS thanks DEGO :)
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SOLUBILITY
Knows as the grams of solute than can be dissolved in 100g of water to form a saturated solution at a particular solution
formula = mass of solute/vol of solvent X 100 = X G PER 100G of OF WATER
ALSO : substance which is more soluble crystallises at lower temperature !. susbt which is less soluble crysttallises at higher temperature because it dissolves at higher temp ..duuuuh!
How to find the the solubilty of a subst at 30 * C?
Burette 100cm3 of disstilled water in a beaker .
Use a thermostatically cotrolled water bath to heat the water till 30*
Then add keep adding exccess of a substance until no more can dissolve!
Immediately filter to seperate excess..
Now filtrate on a PRE-WEIGHED evaporating basin! and heat until dryness ( when basin reaches constant mass )
Mesure weight of basin on an ELECTRONIC BALANCE
Substract the weight of this and the orignal basin. this will be the mass that can dissolves in 100g of water at 30 * C
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EXPERIMENTAL TIPS AND PRECAUTION AND APPARATUS
PESTLE AND MORTAR ( CRUSH ) GAS JAR PIPETTE
GLASS ROD GAS CYLINDER BURETTE
DELIVERY TUBE GAS SYRINGE SEPERATING FUNNEL ( FILTER )
RETORT STAND INVERTED CYLINDER(BEEHIVE) DROPPER PIPPETE
TROUGH BUNG / STOPPER / INLETS /OUTLETS WIRE MESH ( TO HOLD AND ABSORB )
BEAKER CONICAL FLASK Electronic heater
TONGS ROUND BOTTOM FLASK Cotton wool
SPATULA LIEBIG CONDENSOR Boiling tube
EVAP BASIN THERMOMETER Rubber connector
WAIRE GAUZE PH METER CLAMP
HEAT PROOF MAT Electronic balance
TRIPOD Stop clock
In experiments where poisonous gases like BROMINE / AMMONIA / NO2 are given out ..always ifrst thing tht should come to your mind is !!!!!!!!! CARRYYY OUT IN FUMMMMMMMMMEEEEEEEE CUPBOOOOOOOOAAAAAAAAAARD!!! OR WELL VENTILLATED ROOM
In heat experiments use a polysterene cup for insulation to preven heatt loss..use same inital temperature for accurate resuts
In acids and liquids and solids experiments ALWAYS USE..SAME CONCENTTRAION AND SAME VOLUMES AND SAME SURFACE AREA AND SAME MASSES! except for variableS DUUUUUUUUUH
In experiments where crystallisation..alaways allow to cool slowly so you can see when crystallisate happens..and use more volume of water and salt for much more accurate results
In experiments where time can cause error.. you can say use a suspended tube and shake when ready and start stop watch !
IF YOU ARE LOST AND CANT FIND ANY PRECAUTIONS SAY
REPEAT EXPERIMENT FIND AND AVERAGE / TUCK IN TIE IN SHORTS / TIE HAIT WITH HAIRBAND/ SAGETYY GOOGLE.COM..GOGGLES
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RANDOM
SIMPLE DISTILLATION...FRACTIONAL DISTILLATION ..EASY
just remember water is pumped from under the liebig BECAUSE BETTER FLOW OF WATER WCHI COMPLETELY COVERS TUBE FOR BETTER CONDESATION AND COOLING ..and longer fractional columns BETTER SEEPERATION AND PURER DISTILLATE also add bumping granules PROVIDES NUCLEI ON WHICH BBUBBLES CAN GROW LEADING TO SMOOTH BOILING
Also know about sublimation..decanting ... etc
Lime stone caco3 ..quick lime or lime ..cao ...slakes lime or lime watter ca(oh)2
----------------------------------------------------------------------------------------------------------------------
Fementaion
GLUCOSE + YEATS ( enzymes in yeast ) suitable temp of 37 ..optimum temp for working..below that would be slow after that enzyme would denature ! :'(..
Why is there bung ? TO LET CO2 OUT AND TO PREVENT O2 FROM COMING IN!!!!!
What happens if O2 comes in?? bacterial oxidation of alcohol to carboxylic acid ! also yeast wont be able to respier ANEROBICALLY
Why reaction sometimes stops?
GLUCOSE MIGHT FNISH ...YEAST GET KILLED FROM MAKIN ETHANOL FROM GLUCOSE !!
observation of fermantaion : heat ..bubbles of colourless gas..mixture becmes cloudy form cz of multiplication of yeast
---------------------------------------------------------------------------------------------------------------------------
ORGANIC CHEM
FLAMMABLE STUFF ! USE VENTILATION colourless smell like fuel burns with orange smokey flame..immisble
catalytic cracking
--------------------------------------------------------------------- -------------------------------------------------------
COMBUSTION OF METALS
POTASSIUM- BURNS WITH BRIGHT PURPLE LILAC FLAMES REMEMBER FROM P-P PURPLE..
SODIUM - BURNS WITH INTESTE YELLOW FLAMS!!!!!!
MAGNESIUM - BURNS WITH WHITE FLAMES AND FORMS WHITE POWDER.. REMMBER MAGNESIUM WHITE SALTS
DECOMPOSITION OF METALS
NITRATES CARBONATS HYDROXIDES SULFATES
GROUP 1 XCPT LITHIUM forms metal nitrITE + o2 (g) dont decompose dont decompos DO NOT DECOMPOSE
group 2+ lith + trans. met. from metal oxide + 02 + NO2 Metal Oxide + CO2 metal oxide + h2o mmet oxide + so3
( thanks dego :) )
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ELECTROLYSIS AND CELL
Electrolysis converts electrical energy into chemical energy Cell converts chemical intro electrical
Electrolysis has a battery! Voltemeter or bulb..well..not a battery anyway lol..
Electrons move from Cathode to anode.. From Anode to cathode ..
ELECTROPLATING
ALWAYS THE THING BEING ELECTROPLATED IS THE ON THE -VE ( cathode) why??obviously cz the posotive metal has to be attracted to it ..DUUUUHH.. and also the object beign platerd..should no MUST be clean so teh metal can be ADHERED properly AND also MUST be rotated throughout the experiment so the whole object could be elctrplated ..Equal electroplatin on all parts of the object AND ..the electrolyte used is always A METAL NITRATE of the object your are using to elctroplate
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COLLECTION TECHNIQUES THX 6394 :)
upward delivery : gases less dense dan air eg:H2 NH3
downward delivery: gasses more dense den air eg:hydrogen chloide ,CO2
displacement of water :for insoluble gases eg:hydrogen methane
ALWAYS COMPARE AND SHOW RESULTS AND CONCLUDE AND REPEAT
THATS ALL I HAVE IN MY MIND FOR PAPER 6 CHEM..anythign i have to add please tell me!!?
and send me any messages for question !!!!!!!!!!!!!
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good questionst to do
titration : M/J 2000 Q6
CRYSTALLISTION : NOV 2000 Q 3
ANALYSIS : M/J 1999 Q 5
HARDERS PAPER IV EVER DOEN IS MAY 1999 GOODLUCK !
IF I MISSED ANYTHING IT WOULD BE THE TEST FOR CATIONS AND ANIONS..I CANT WRITE IT DOWN FOR YOU ALL I CAN SAY IS THAT YOU HAVE TO LEARN IT BY HEART AND I CANT STRESS ENOUGH ON HOW IMPORTANT THAT IS !
[/list]
Any paper 6 doubts , tips , "helps" , questions be put here
goodluck to all >.<
Please critisize the information. and help increase it
ILL UPDATE WHEN I CAN :-*
SOLUBLE COMPOUNDS INSOLUBLE COMPOUNDS
ALL Na, Potassium , Ammonium salts -
All Nitrates ( Best for electrollytes ) ;) -
All Sulfates Except Barium Lead nd Calcium ( L , B , C) <--good way to learn
Na,potassium , ammonium Carbonates All other carbonates
All Halides Except Silver & Lead ( the anions test remember )??
----------------------------------------------------------------------------------------------------------------------
OXIDISING AGENSTS : KMn04 (V11) FROM PURPLE TO COLOURLESS / K2Cr2O7 (V1) FROM ORANGE 2 GREEN / HALIDES
REDUCING AGENTS : ALL METALS ..
Dehydrating Agents : Sulfuring Acid , Calcium Oxide
----------------------------------------------------------------------------------------------------------------------
CHEMICAL
TEST FOR WATER:1. COBALT (11) CHLORIDE PINK TO BLUE
2. WHITE ANHYDROUS COPPER (11) SULFATE TO BLUE becomes hydrated
PHYSICAL
B.P AND M.P SHOULD MELT AT FIXED POINTS! NOT RANGE !!
-----------------------------------------------------------------------------------------------------------------------
By Chromatography. Place Concentrated spot on chromatography paperon the datum line which is drawn in pencil ( isnoluble , so does not affect results ). suspend it in solvent so as the solvent level is below the datum line. Wait for solvent to reach till end of the paper. Now..depending upon the question you say..:
1.Check for different dyes because there are diffrent spots.
2.Spray locating agent if there is amino acids or starch...cz they are colourless
3.identify by RF values : dist. moved by dye/dist moved by solvent.
Chromatography is used to identify and seperate a MIXTURE of subtances according to their different solubilties in water and their attraction to the chromatography paper
---------------------------------------------------------------------------------------------------------------------------
DO NOT FORGET DAMP LITMUS PAPER !!!!
test of oxygen : GLOWING SPLINT : RELIGHTS! [HYDROGEN PEROXIDE + MANGANESE 4 OXIDE ]
test 4 hydrogeb :LIGHTED SPLINT : SQUEAKY POOOP![ HCL + MG RIBBON ]
test 4 ammonia (aq) : turns red litmus paper blue [AMMONIUM CHLORIDE + NAOH]
test 4 chlorine : turn litmus paper red then bleeches it[KMnO4 + HCL ]
test 4 carbon dioxide : buble thro limewater..turns from colourless to milky white [CALCIUM CARBONATE + HCL ]
---------------------------------------------------------------------------------------------------------------------------
tests , experimental techniques and apparatus and important words to use coming up sooooon!!
INSOLUBLE COMPOUNDS : All hydroxides except those of Group I, Strontium, Calcium and Barium