paper 3 scheme first mid term 2016

1. Skema jawapan K3
1a) Burette reading:49.60 cm3
, 39.60 cm3
, 30.10 cm3
,21.60 cm3
, 15.10 cm3
,11.10 cm3
, 8.10 cm3
,
8.10 cm3
bi)
Time (s) 0 30 60 90 120 150 180 210
Burette reading(cm3
) 49.60 39.60 30.10 21.60 15.10 11.10 8.10 8.10
Volume of gas(cm3
) 0.00 10.00 19.50 28.00 34.50 38.50 41.50 41.50
ii) The volume of the gas increaseswithtime until t=180 s and thenremainconstant.
iii) –both axesare labeledandwithunits
Y –axis: Volume of CO2 (cm3
)
X- axis:Time (s)
- Uniformscale
- All points transferredcorrectly
- Smoothcurve
- Size mustbe more than 50% of the graphpaper
ci) MV: Size of calciumcarbonate/Total surface areaof calciumcarbonate
ii) RV:Rate of reaction/Volume of carbondioxidegas
iii) CV:Volume andconcentrationof HCl / Mass of calciumcarbonate
d) Hypothesis:The smallerthe size of calciumcarbonate,the higherthe rate of reaction// Whenthe
total surface area of calciumcarbonate increases,the rate of reactionincreases.
e) – The smallersize of calciumcarbonate hasa largertotal surface area
- The frequencyof effective collisionbetweencalciumcarbonate andhydrogenionishigher
- The rate of reactionishigher
2a) Ammeterreadings:2.6A, 0.0 A,0.0 A,3.6 A.
b)
Electrolyte Non-electrolyte
NaCl solution Ethanol
Lead (II) nitrate solution Glucose
ci) The ammeterreadingdecreases//The ammeterreadingislessthan2.6A
ii) – H+ ionsand Cl- ionsdischarged
- Concentrationof free movingionsdecreases
- Electrical conductivitydecreases//Amountof currentdecreases

2. 3a) Statementof problem:Howdoesthe temperature of sodiumthiosulphate solutionaffectthe
rate of its reactionwithsulphuricacid?
b)
MV: Temperature of sodiumthiosulphatesolution
RV: The rate of reaction
FV /CV:Volume andconcentrationof sodiumthiosulphate solution,volume andconcentrationof
dilute sulphuricacid.
c) Statementof hypothesis:Whenthe temperature of sodiumthiosulphatesolutionincreases,the
rate of its reactionwithsulphuricacidincreases.
d) List of apparatus:
Conical flask,measuringcylinder,stopwatch,thermometer
List of apparatus:
Sodiumthiosulphate solution,sulphuricacid,distilledwater.
e) Procedure:
1. 50 cm3
of sodiumthiosulphate solutionismeasuredandpouredintoaconical flask.
2. The temperature of thissolutionismeasuredusingthermometerandrecorded.
3. The conical flaskisplacedon top of a piece of paperwitha mark ‘x’at the centre.
4. 5 cm3 of sulphuricacidismeasuredandpouredquicklyandcarefullyintothe conical flask.
5. Swirl the conical flaskatthe same time startthe stopwatch.
6. The mark ‘x’is observed.
7. The stopwatchis stoppedimmediatelywhenthe mar‘x’isno longervisible.
8. The time takenfor the mark ‘x’isno longervisibleisrecorded.
9. Step1 to 8 are repeatedbyheatingthe solutiontoahighertemperature of 35⁰C,40⁰C,
45⁰C, 50⁰C and 55⁰C.
f) Tabulationof data:
Temperature/⁰C 30 35 40 45 50 55
Time takenformark ‘x’to disappear/s
1/time / s-1