Measuring Temperature
Minilab
Name_________________________________
Date_________ Block______
Purpose: to gain experience measuring temperature with a Celsius thermometer
Materials: 250-mL beaker, alcohol-filled Celsius thermometer, tap water,
ice cubes, watch/clock with second hand
Procedure:
1) Read all steps in the Procedure before starting to follow the steps.
Make a 2-column data table: title for the data table: Temperature (oC) vs Time (seconds)
Label the first column: Time (s)
Label the second column: Temperature (oC).
You will need about 20 rows for data.
Your first entry for Time (s) should be “00” (time zero) as your starting time.
Make entries for time in intervals of 15 seconds until you have 20 entries:
Time (s)
00
15
30
45
60
75
90
105
120
135
etc., etc., for a total of 20 entries
2) Place about 150-mL tap water into the beaker. Use the 150-mL mark on the beaker.
3) Place the thermometer into the water and wait until the level of the red-tinted alcohol
becomes stable at one temperature marking.
4) Carefully read the temperature of the water and record the temperature at “time zero” –
this will be the starting temperature. Be sure to record all significant figures!!!!!
5) Add about 3-4 ice cubes to the beaker of water. GENTLY stir the ice-water with the
thermometer. Every 15 seconds, measure the temperature of the ice-water mixture.
Record the temperature using sig. figs. Keep ice in the beaker at all times.
6) Continue stirring, measuring and recording the temperature every 15 seconds until you have
completed your data table with 20 entries.
7) Graph the data: Temperature (oC) vs Time (s)
Time is ALWAYS the independent variable regardless of what time unit is used.
The lowest value for the temperature (on the y-axis) should be at the intercept with the x-axis.
8) Draw the line-of-best-fit with a ruler, having the line intercept the y-axis at time zero.
Analysis of Graph of Temperature (oC) vs Time (s)
1. What is the general relationship between temperature and time for liquid tap water that
has ice added to it?
2. If your measurements of temperature “leveled off,” that is, after a while, the
temperature did not change for several measurements, what is the temperature at the
plateau (the “level-off” temperature)?
________________________
Measuring Amount of Heat Loss
Minilab
Name_______________________________
Date_________ Block____
Purpose:
1) to apply skills learned in previous lab on Temperature
2) to calculate the amount of heat lost by a given mass of tap water during a 10-min. time period
Materials:
plastic cup
hot tap water
400-mL or 600-mL beaker
ice cubes
thermometer
clock
electronic balance
Procedure:
1) Place several (3-4) ice cubes into the large beaker and add tap water to about half the
capacity of the beaker.
2) Determine the mass of an empty, dry plastic cup.
3) Fill the plastic cup with hot water to about 3/4 capacity of the cup.
4) Place the cup with water on the balance and determine the mass of the water alone.
(Measure the mass of the cup + water. Subtract the mass of the empty, dry cup from the
mass of the cup + water.) Record the mass of the water alone in the data table.
5) Using the thermometer, measure the temperature of the water in the plastic cup. Record the
temperature as “T1” in the data table.
6) Place the plastic cup with water into the large beaker containing ice and water. Do not allow
the plastic cup to tip or to allow water from the large beaker to flow into the plastic cup.
7) After 10 minutes have passed, remove the plastic cup from the large beaker of ice and water.
8) Measure the temperature of the water in the plastic cup. Record the temperature as “T2” in
the data table.
9) Carefully and thoroughly dry the outside of the plastic cup. Do not spill any water.
10) Calculate the amount of heat energy that was lost from the water during the 10 minutes.
Data Table
Mass (g) of water
in the plastic cup
Starting
Temp (oC)
T1
Ending
Temp (oC)
T2
Calculation. Use the equation: Q = m x ΔT x c
where Q is the amount of heat gained or lost in joules (J)
m is the mass of the water alone in the plastic cup
ΔT is the change in temperature (T2 – T1)
c is the specific heat of water: 4.18 J/(g)(oC)
Be sure to show units cancelled!
You will have a negative value for Q since heat was lost from the water.