Report On Exp 8

Materials: • • • • • •

Microcalorimeter (styrofoam, film canister) Thermometer Watch glass Pipette Beaker Anhydrous CaCl2

• • • •

NaCl (s) KCl (s) KBr (s) KI (s)

Set-up

Movable thermometer Film Canister Sample

Styrofoam box

Procedures: Pipette 20 mL of water to the calorimeter, let stand for 15 Measure the temperature of the water Weigh 1.0 + 0.01 g CaCl2 in a watch glass Add the crystals to the water in the calorimeter and read the temperature change every 5 seconds while swirling until 10 readings Plot the temperature readings and determine the equilibrium temperature Repeat the steps using 1.5, 2.0, 2.5, 3.0 g of CaCl2 Repeat the steps using 18.0, 16.0, 14.0, and 12.0 mL of H2O Repeat the steps using NaCl, KCl, KBr and KI in place of CaCl2

Suggested Improvements and other Possible methods

Other possible Set-ups

Other possible Set-ups

Other possible Set-ups

Other possible Set-ups

Different Procedure

Experimental setup: the glass beaker on the left contains hydrous CaCl2; the one on the right, anhydrous CaCl2

Addition of Water

The temperature of hydrous calcium chloride falls

The temperature of anhydrous calcium chloride rises