Solution

a) The calibration factor is calculated by the expression below.

b) To calculate the enthalpy change

Step 1) Work out the mole of calcium chloride added

Mole of calcium chloride added = 2.456 /111 = 0.022 mole

Step 2) Calculate the amount of energy released by the dissociation of calcium chloride

calibration factor X temperature change = 142.14 X 5.88 = 835.78 joules or 0.84Kj

The enthalpy change is given by the expression
energy given out/mole = 0.84/ 0.022 = -38.0kj/mol

Note the enthalpy change is negative indicating that energy is given out.

 

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