AQA A LEVEL CHEM REQUIRED PRACTICALS
LEARN!!! QUIZZES WITH ACTUAL ANSWERS.
Required,practical,1a,making,a,standard,solution,method,,,ANS,-
1.,Weigh,the,sample,bottle,containing,the,required,mass,of,solid,on,a,2,dp,balance
2.,Transfer,to,a,beaker
3.,Reweigh,the,empty,sample,bottle
4.,Record,the,difference,in,mass
5.,Add,100cm3,of,distilled,water,to,the,beaker,,use,a,glass,rod,to,stir,to,help,dissolve,the,solid
6.,Pour,solution,into,a,250cm3,graduated,flask,via,a,funnel
7.,Rinse,beaker,and,funnel,and,add,washings,from,the,beaker,and,glass,rod,to,the,volumetric,flask
8.,Make,up,to,the,mark,with,distilled,water,using,a,dropping,pipette
9.,Invert,flask,several,times,to,ensure,a,uniform,distribution
Required,practical,1b,titrations,method,,,ANS,-
1.,Rinse,equipment:,burette,with,acid,,pipette,with,alkali,and,conical,flask,with,distilled,water,
2.,Pipette,25cm3,of,alkali,into,conical,flask
3.,Touch,surface,of,alkali,with,pipette,(to,ensure,the,correct,amount,is,added)
4.,Add,acid,solution,from,burette
5.,Make,sure,that,the,jet,space,in,the,burette,is,filled,with,acid
6.,Add,a,few,drops,of,indicator,and,refer,to,colour,change,at,end,point
7.,Phenolphtalein,(pink,-,alkali,to,colourless,-,acid),end,point:,pink,colour,disappears
8.,Methyl,orange,(yellow,-,alkali,to,red,-,acid),end,point:,orange
9.,Use,a,white,tile,underneath,the,flask,to,help,observe,the,colour,change
10.,Add,acid,to,alkali,whilst,swirling,the,mixture,and,add,drop,wise,at,end,point
11.,Note,burette,reading,before,and,after,addition,of,acid
12.,Repeat,the,titration,until,at,least,2,concordant,results,are,obtained,-
,two,readings,within,0.1cm3,of,each,other
, Reason,for,larger,than,expected,titre,reading,during,a,titration,,,ANS,-
If,the,jet,space,in,the,burette,is,not,filled,properly
Required,practical,2,method,,,ANS,-
1.,Wash,the,equipment,(cups,and,pipettes,etc),with,the,solutions,to,be,used
2.,Dry,the,cup,after,washing
3.,Put,polystyrene,cup,in,a,glass,beaker,for,insulation,and,support
4.,Measure,out,desired,volumes,of,solutions,with,volumetric,pipettes,and,transfer,to,insulated,cup
5.,Clamp,thermometer,into,place,making,sure,the,thermometer,bulb,is,immersed,in,solution,
6.,Measure,the,initial,temperatures,of,the,solution,or,both,solutions,if,2,are,used.,Do,this,every,minute,for
,2-3,minutes
7.,At,minute,3,transfer,second,reagent,to,cup.,If,a,solid,reagent,is,used,then,add,the,solution,to,the,cup,fir
st,and,then,add,the,solid,weighed,out,on,a,balance.,
8.,If,using,a,solid,reagent,then,use,'before,and,after',weighing,method,
9.,Stir,mixture,(ensures,that,all,of,the,solution,is,at,the,same,temperature),
10.,Record,temperature,every,minute,after,addition,for,several,minutes
Errors,in,required,practical,2,,,ANS,--energy,loss,from,surroundings
-reaction,or,dissolving,may,be,incomplete,or,slow
Suggest,why,aqueous,ethanol,is,a,suitable,solvent,when,heating,the,coconut,oil,with,KOH.,Give,a,safety,pr
ecaution,used,when,heating,the,mixture.,Justify,your,choice.,,,ANS,-To,dissolve,both,oil,and,KOH,
Precaution:,Use,a,water,bath,for,heating,mixture,
Prevents,risk,of,fire,/,Ethanol,is,flammable
Suggest,why,the,1.0,cm3,portions,of,the,reaction,mixture,are,added,to,an,excess,of,NaHCO3,solution.,,,AN
S,-The,sodium,hydrogen,carbonate,solution,neutralises,the,acid,(catalyst),So,stops,the,reaction
Suggest,why,the,order,of,this,reaction,with,respect,to,propanone,can,be,ignored,in,this,experiment.,,,ANS,
-The,concentration,of,propanone,is,much,larger,than,the,concentration,of,iodine,
Concentration,of,propanone,is,(almost),constant
LEARN!!! QUIZZES WITH ACTUAL ANSWERS.
Required,practical,1a,making,a,standard,solution,method,,,ANS,-
1.,Weigh,the,sample,bottle,containing,the,required,mass,of,solid,on,a,2,dp,balance
2.,Transfer,to,a,beaker
3.,Reweigh,the,empty,sample,bottle
4.,Record,the,difference,in,mass
5.,Add,100cm3,of,distilled,water,to,the,beaker,,use,a,glass,rod,to,stir,to,help,dissolve,the,solid
6.,Pour,solution,into,a,250cm3,graduated,flask,via,a,funnel
7.,Rinse,beaker,and,funnel,and,add,washings,from,the,beaker,and,glass,rod,to,the,volumetric,flask
8.,Make,up,to,the,mark,with,distilled,water,using,a,dropping,pipette
9.,Invert,flask,several,times,to,ensure,a,uniform,distribution
Required,practical,1b,titrations,method,,,ANS,-
1.,Rinse,equipment:,burette,with,acid,,pipette,with,alkali,and,conical,flask,with,distilled,water,
2.,Pipette,25cm3,of,alkali,into,conical,flask
3.,Touch,surface,of,alkali,with,pipette,(to,ensure,the,correct,amount,is,added)
4.,Add,acid,solution,from,burette
5.,Make,sure,that,the,jet,space,in,the,burette,is,filled,with,acid
6.,Add,a,few,drops,of,indicator,and,refer,to,colour,change,at,end,point
7.,Phenolphtalein,(pink,-,alkali,to,colourless,-,acid),end,point:,pink,colour,disappears
8.,Methyl,orange,(yellow,-,alkali,to,red,-,acid),end,point:,orange
9.,Use,a,white,tile,underneath,the,flask,to,help,observe,the,colour,change
10.,Add,acid,to,alkali,whilst,swirling,the,mixture,and,add,drop,wise,at,end,point
11.,Note,burette,reading,before,and,after,addition,of,acid
12.,Repeat,the,titration,until,at,least,2,concordant,results,are,obtained,-
,two,readings,within,0.1cm3,of,each,other
, Reason,for,larger,than,expected,titre,reading,during,a,titration,,,ANS,-
If,the,jet,space,in,the,burette,is,not,filled,properly
Required,practical,2,method,,,ANS,-
1.,Wash,the,equipment,(cups,and,pipettes,etc),with,the,solutions,to,be,used
2.,Dry,the,cup,after,washing
3.,Put,polystyrene,cup,in,a,glass,beaker,for,insulation,and,support
4.,Measure,out,desired,volumes,of,solutions,with,volumetric,pipettes,and,transfer,to,insulated,cup
5.,Clamp,thermometer,into,place,making,sure,the,thermometer,bulb,is,immersed,in,solution,
6.,Measure,the,initial,temperatures,of,the,solution,or,both,solutions,if,2,are,used.,Do,this,every,minute,for
,2-3,minutes
7.,At,minute,3,transfer,second,reagent,to,cup.,If,a,solid,reagent,is,used,then,add,the,solution,to,the,cup,fir
st,and,then,add,the,solid,weighed,out,on,a,balance.,
8.,If,using,a,solid,reagent,then,use,'before,and,after',weighing,method,
9.,Stir,mixture,(ensures,that,all,of,the,solution,is,at,the,same,temperature),
10.,Record,temperature,every,minute,after,addition,for,several,minutes
Errors,in,required,practical,2,,,ANS,--energy,loss,from,surroundings
-reaction,or,dissolving,may,be,incomplete,or,slow
Suggest,why,aqueous,ethanol,is,a,suitable,solvent,when,heating,the,coconut,oil,with,KOH.,Give,a,safety,pr
ecaution,used,when,heating,the,mixture.,Justify,your,choice.,,,ANS,-To,dissolve,both,oil,and,KOH,
Precaution:,Use,a,water,bath,for,heating,mixture,
Prevents,risk,of,fire,/,Ethanol,is,flammable
Suggest,why,the,1.0,cm3,portions,of,the,reaction,mixture,are,added,to,an,excess,of,NaHCO3,solution.,,,AN
S,-The,sodium,hydrogen,carbonate,solution,neutralises,the,acid,(catalyst),So,stops,the,reaction
Suggest,why,the,order,of,this,reaction,with,respect,to,propanone,can,be,ignored,in,this,experiment.,,,ANS,
-The,concentration,of,propanone,is,much,larger,than,the,concentration,of,iodine,
Concentration,of,propanone,is,(almost),constant
