PASCO Xplorer-GLX Users’ Guide - Manual (Page 117)

X p l o r e r G L X U s e r s ’ G u i d e 111
A c t i v i ty 2 : M e l t i n g P o i n t D e p r e s s i o n
Background
How does the addition of salt affect the melting point of a solution? In this exper-
iment, you will measure the temperature over time of frozen salt water and pure
water as they melt. From the recorded data, you will identify and compare the
melting points of both liquids.
Pre-lab: Prepare Frozen Solutions
Prepare the frozen solutions at least one day in advance.
1. Make a solution of 1 g NaCl in 100 ml of deionized water. Add enough to a
test tube to fill it to a depth of about 1 cm.
2. Add the same amount of deionized water to a second identical test tube.
3. Place a fast-response temperature probe in each test tube. The ends of the
probes should be immersed. Use tape to secure the probes in place.
4. Label both test tubes and label the connectors of both probes for easier iden-
tification.
5. Place both test tubes (along with the probes) in a freezer.
Before You Begin
Start a new experiment on the GLX.
1. Press to go to the Home Screen.
2. Use the arrow keys to highlight the Data Files icon and press to open
the Data Files screen.
3. Press to open the Files menu and press to select New File.
4. When the GLX asks if you would like to save the previous file, press
to save or not to save.
Equipment Quantity
Xplorer GLX 1
Fast-response Temperature
Probes
2
Test Tubes 2
Test Tube Rack 1
Deionized Water 110 mL
NaCl 1 g
Temperature
Probe
Tape
to be connected
to the GLX
F4 1 pqrs
F1
F2