Construct Ionic Equations Through Continuous Variation Method
NURUL ASHIKIN BT ABD RAHMAN (UPSI) -PEKA KIMIA 3-
Instrument : Laboratory ReportDate : 00 September 2012Title : Construct Ionic Equation
AIMTo construct a ionic equation for the formation lead (II) chromate (VI) based on the continuous variation reaction method.
PROBLEM STATEMENTHow to determine the ionic equation for precipitation of lead (II) chromate (VI)?
Hypothesis
The height of precipitate will increase with the volume of potassium chromate (IV) solution until
all the lead (II) nitrate has reacted.
VariableManipulated : Volume of potassium
chromate (IV)Responding : height of precipitateFixed : volume and molarity lead (II)
nitrate, molarity potassium chromate (IV),size of
test tube.
CHEMICAL
Potassium Chromate (IV) (0.5 M)
Lead (II) Nitrate(0.5 M)
APPARATUS
Test tube rack
Test tube
Rubber stopper
APPARATUS
Burette (50cm)
Ruler
Retort stand
FIGURE
PROCEDURE
REFER PRACTICAL BOOK
CHEMISTRY FORM 4
PAGE???
OBSERVATION
Test Tube 1 2 3 4 5 6 7 8
Volume of Pb(NO3)2 solution 0.5 M(cm3)
5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0
Volume of K2CrO4 solution 0.5 M(cm3)
1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
Precipitate height (cm) 1.0
Colour of solution
Graph Height of precipitate (cm) against Volume K2CrO4 solution 0.5 M (cm3)
0 1 2 3 4 5 6 7 80
1
2
3
4
5
6 Height of precipitate (cm)
Volume K2CrO4 (cm3)
ANALYSING & INTERPRETING DATA
Volume of CrO42-
ions used to precipitate all the
Pb2+ ions
What is the volume of K2CrO4 solution (cm3) required to fully react with 5 cm3 Pb(NO3)2 solution ?
Mole K2CrO4 = ?Mole Pb(NO3)2 = ? n = MV
Ratio ?Ionic Equation?
DISCUSSION
Why the volume Pb(NO3)2 are fixed?Why some of solution remain yellow?and why
some of solution will be colourless?Refer page 123 practical book form 4
CONCLUSION
Ionic Equation ?Hypothesis accepted or not?