Casio EA-200, EA200 m“E-CON”w1(SETUP)b(Wizard)w, 1(CASIO)c(TEMP)b(°C) 5w240w1(YES)

Activity: Operating the Equipment

￿Measuring Data

uMeasure the mass of the beaker used for creating the solution.

uSlowly pour the benzene into the beaker so it flows down the inside surface of the beaker.

uMeasure the mass of the small amount of naphthalene being used.

uDissolve the small amount of naphthalene to create a dilute benzene solution, and then measure the mass of the solution.

uCalculate the molality of the naphthalene.

uDivide the dilute benzene solution between two flasks, pouring the solution slowly along the inside surfaces of the flasks.

uSecure one of the flasks in the boiling point elevation system, and the other one in the freezing point depression system.

1Benzene

2Naphthalene

3Beaker

4Round Bottom Flask

5Naphthalene-Benzene Solution

uAs shown in the illustration, force water through the reflux condenser.

1Reflux Condenser

2Tap

3Water Flow Direction

4Open the tap.

uFor boiling point elevation, turn on the heater and use the Temperature Measurement Setup to measure the temperature.

uFor freezing point depression, turn on the auto stirrer and use the Temperature Measurement Setup to measure the temperature.

uUse the measured changes in temperature to determine boiling point elevation and freezing point depression.

uCompare the measured results with the results calculated from naphthalene molality.

For freezing point depression, use the mixing stick to stir the flask contents.

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English

Measurementasurement

￿Calculator Operation

uPerform the following operation to prepare for temperature measurement using the Temperature Measurement Setup.

Using E-CON

m“E-CON”w1(SETUP)b(Wizard)w

1(CASIO)c(TEMP)b(°C) 5w240w1(YES)

Using a Calculator Program

Find the applicable program in the Program Library (P.2-16-3), input it into your calculator, and then run it.

uDisplay a graph of temperature change starting from the point that the solution is first heated.

T(°C) : Temperature

t(s) : Time

T1(°C): Solution Boiling Point

uDisplay a graph of temperature change starting from the point that the solution is first cooled.

T(°C) : Temperature

t(s) : Time

T2(°C): Solution Freezing Point

55555555555555555555555Other Things To Do

	u Consider how the molecular weight of naphthalene can be determined using the
	measurement results.
	u Consider why the cooling curve of freezing point depression is not clear.
	u Create another dilute solution using a different solute, and determine the boiling
5555555	point elevation and the freezing point depression.	5555555
	point elevation and the freezing point depression.
	u Create another dilute solution using a different solvent, and determine the boiling
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