Determine enthalpy change of single displacement reaction between zinc and copper sulphate
Introduction:
Zinc is placed at a higher position in the activity series compared to copper. Hence zinc can displace copper from a solution of copper sulphate. During this displacement reaction, heat evolved can be calculated in kJmol-1. The amount of heat evolved can be used to determine the relative position of metals in the activity series.
Chemical:
Apparatus:
Styrofoam cup with lid
Zinc powder (1.0 g)
Temperature probe
1.0 mol.dm-3 copper sulphate solution
25.0mL volumetric pipette
Preparation:
Write a balanced equation for this displacement reaction.
Procedure:
· Pipette 25.0mL of 1.0 mol.dm-3 CuSO4 into a styrofoam cup.
· Weigh around 1.0 g of zinc powder and record the exact mass.
· Put the temperature probe through the hole代 写Determine enthalpy change of single displacement reaction between zinc and copper sulphateR
in the lid, stir and record the temperature to the nearest 0.1oC every half minute for 2.5 minutes.
· At precisely 2.5 minutes, add the zinc powder to the cup.
· Continue stirring and record the temperature till there are at least 5 readings where the temperature has dropped from the previous reading.
Data Collected
Analysis 1 Calculate the heat of the reaction by using q = mcDT,
c = 4.18 Jg-1°C-1 and DT is the change in temperature.1 Convert the heat of the reaction (in joules) to kJ mol–1 of limiting reagent2 Show the propagation of uncertainties in your calculationsDiscussion: Evaluate your experiment. What assumptions did you make?The literature value for this displacement reaction is -218kJmol-1. Calculate the % error and mention some sources of error and how precise (replicable) your results were. (the class results)
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