PRACTICALS CHEMISTRY AQA A-LEVEL
QUIZZES WITH 100% CORRECT VERIFIED
ANSWERS.
Required,Practical,1,-,titration,and,making,a,standard,solution
Making,a,standard,solution,,,ANS,-
1.,weigh,the,required,mass,of,solid,using,a,sample,bottle,on,a,2,dp,balance.,
2.,transfer,the,solid,into,a,beaker,using,distilled,water,to,wash,it,out-
,preventing,any,solid,remaining,in,the,sample,bottle.
3.,reweigh,the,sample,bottle,and,work,out,the,difference.,
4.,Add,100cm3,of,distilled,water,to,the,beaker,to,dissolve,the,solid,(small,volume,of,water),using,a,stirring,
rod,to,evenly,distribute,the,solution.,
5.transfer,the,dissolved,solution,into,a,250cm3,graduated,volumetric,flask,using,a,funnel,,rinsing,contents
,of,the,beaker,and,stirring,rod,with,distilled,water,into,the,flask.,
6.,make,up,the,solution,to,250cm3,by,adding,more,distilled,water,,using,a,dropping,pipette,for,the,last,fe
w,drops.,making,sure,the,bottom,of,the,meniscus,is,touching,the,line,marking,250cm3.
7.,invert,the,volumetric,flask,several,times,to,ensure,that,the,solution,is,uniform/evenly,distributed.
Required,Practical,1,Making,a,solution,and,acid-base,titration
Acid-Base,Titration,(neutralisation)/redox,titration,,,ANS,-1.,Rinse,the,equipment,-
,with,the,solutions,that,they,will,contain,e.g.,pipette,washed,w/,alkali/standard,solution,,burette,rinsed,wi
th,the,known,sol,conc./acid,and,the,conical,flask,is,rinsed,w/,distilled,water.,
, 2.,Pipette,25cm3,of,alkali/standard,solution,into,a,conical,flask.,touch,the,end,of,the,pipette,in,the,alkali/s
tandard,sol,once,in,the,conical,flask,-,ensures,the,correct,amount,of,alkali,has,been,added.,
3.,Add,the,known,conc.,sol,into,the,burette,using,a,funnel-,prevents,spillages,of,sol.,
4.,Add,a,few,drops,of,indicator,to,the,conical,flask,(phenolphthalein,pink,in,alkali,and,colourless,in,acid),
5.,Place,a,white,tile,under,the,conical,flask,-,to,accurately,observe,the,colour,change.,
6.,Add,the,acid,to,the,alkali,/,known,sol,to,unknown,-
,swirling,the,conical,flask.,Add,drop,wise,as,the,reaction,reaches,it's,end,point.,
7.,repeat,until,2,concordant,results,are,obtained.,within,0.1,of,each,other.,
record,the,initial,titre,,final,titre-,Titre.,
To,find,the,conc.,of,the,unknown,sol.
Why,is,a,volumetric,pipette,more,accurate,than,a,measuring,cylinder?,,,ANS,-
because,it,has,a,smaller,uncertainty
Why,use,a,conical,flask,and,not,a,beaker?,,,ANS,-conical,flask,is,easier,to,swirl
Why,only,use,small,drops,of,indicator?,,,ANS,-indicators,tend,to,be,weak,acids,-
,so,adding,too,much,will,affect,the,result,of,the,titration.
how,do,you,reduce,percentage,uncertainty,in,a,titration?,,,ANS,--
,replacing,any,measuring,cylinders,with,pipettes,and,burettes,which,have,a,lower,apparatus,uncertainty.,
-,increase,the,vol,and,conc.,of,the,substance,in,the,conical,flask,
QUIZZES WITH 100% CORRECT VERIFIED
ANSWERS.
Required,Practical,1,-,titration,and,making,a,standard,solution
Making,a,standard,solution,,,ANS,-
1.,weigh,the,required,mass,of,solid,using,a,sample,bottle,on,a,2,dp,balance.,
2.,transfer,the,solid,into,a,beaker,using,distilled,water,to,wash,it,out-
,preventing,any,solid,remaining,in,the,sample,bottle.
3.,reweigh,the,sample,bottle,and,work,out,the,difference.,
4.,Add,100cm3,of,distilled,water,to,the,beaker,to,dissolve,the,solid,(small,volume,of,water),using,a,stirring,
rod,to,evenly,distribute,the,solution.,
5.transfer,the,dissolved,solution,into,a,250cm3,graduated,volumetric,flask,using,a,funnel,,rinsing,contents
,of,the,beaker,and,stirring,rod,with,distilled,water,into,the,flask.,
6.,make,up,the,solution,to,250cm3,by,adding,more,distilled,water,,using,a,dropping,pipette,for,the,last,fe
w,drops.,making,sure,the,bottom,of,the,meniscus,is,touching,the,line,marking,250cm3.
7.,invert,the,volumetric,flask,several,times,to,ensure,that,the,solution,is,uniform/evenly,distributed.
Required,Practical,1,Making,a,solution,and,acid-base,titration
Acid-Base,Titration,(neutralisation)/redox,titration,,,ANS,-1.,Rinse,the,equipment,-
,with,the,solutions,that,they,will,contain,e.g.,pipette,washed,w/,alkali/standard,solution,,burette,rinsed,wi
th,the,known,sol,conc./acid,and,the,conical,flask,is,rinsed,w/,distilled,water.,
, 2.,Pipette,25cm3,of,alkali/standard,solution,into,a,conical,flask.,touch,the,end,of,the,pipette,in,the,alkali/s
tandard,sol,once,in,the,conical,flask,-,ensures,the,correct,amount,of,alkali,has,been,added.,
3.,Add,the,known,conc.,sol,into,the,burette,using,a,funnel-,prevents,spillages,of,sol.,
4.,Add,a,few,drops,of,indicator,to,the,conical,flask,(phenolphthalein,pink,in,alkali,and,colourless,in,acid),
5.,Place,a,white,tile,under,the,conical,flask,-,to,accurately,observe,the,colour,change.,
6.,Add,the,acid,to,the,alkali,/,known,sol,to,unknown,-
,swirling,the,conical,flask.,Add,drop,wise,as,the,reaction,reaches,it's,end,point.,
7.,repeat,until,2,concordant,results,are,obtained.,within,0.1,of,each,other.,
record,the,initial,titre,,final,titre-,Titre.,
To,find,the,conc.,of,the,unknown,sol.
Why,is,a,volumetric,pipette,more,accurate,than,a,measuring,cylinder?,,,ANS,-
because,it,has,a,smaller,uncertainty
Why,use,a,conical,flask,and,not,a,beaker?,,,ANS,-conical,flask,is,easier,to,swirl
Why,only,use,small,drops,of,indicator?,,,ANS,-indicators,tend,to,be,weak,acids,-
,so,adding,too,much,will,affect,the,result,of,the,titration.
how,do,you,reduce,percentage,uncertainty,in,a,titration?,,,ANS,--
,replacing,any,measuring,cylinders,with,pipettes,and,burettes,which,have,a,lower,apparatus,uncertainty.,
-,increase,the,vol,and,conc.,of,the,substance,in,the,conical,flask,
