The purpose of this lab was to measure the heat of solution through heating the two solutions Na2S2O3 and NaC2H3O2 that we used for solutes.
Procedure.
Prepared the data table with five columns. Prepared a cold water-bath. A small plastic water-tub with ice was filled in. Fill a 600mL beaker three-fourths full of distilled water. Made a hole in the ice large enough for the beaker.Cut a square of corrugated cardboard slightly larger than the top of the plastic foam cup.Made a hole in the center of the cardboard piece with a cardboard throw a pencil. Make a second hole in the center. Insert a piece of wire through the hole, and bend each end to make 1.0cm loops.
Insert a thermometer or thermistor probe into the center hole, and set the entire assembly aside until repeated pour the cold water from the cylinder into the plastic foam cup. On a piece of weighing paper, the mass of approximately 15 g of Na2C2H3O2 has been measured. The chemical has been poured into a small test tube. Record the mass of the Na2C2H3O2 in the Data Table.Pour approximately 75 mL of the cold water from step 1 into a 100 mL graduated cylinder. Record the volume to the nearest 0.1 mL in the Data Table.Pour the cold water from the graduated cylinder into the plastic foam cup.Put the thermometer or thermistor assembly into the cup.
The bulb of the thermometer should be completely covered by the water but must not touch the bottom of the cup. Record the temperature of the cold water to the nearest 1.0 °C in the Data Table. Lift the cardboard slightly, and dump the entire contents of the Trial 1 test tube into the plastic foam cup. Gently moved the stirring Wire up and down inside the cup to disperse the heat. Allow the solid to dissolve completely. Stirred continuously until the temperature of the water peaks.Record the highest temperature reached by the water to the nearest l.0 ËšC if using a thermometer or to the nearest 0.1ËšC if using a thermistor probe.