Boiling Point Lab
 Use the cheat sheet to help
you complete your lab report!!
Boiling Point Lab Report
 PURPOSE:
 The purpose of this
experiment is to determine
the amount of salt in an
unknown water sample by
determining its boiling point
Boiling Point Lab Report
 BACKGROUND INFO:
 List and describe details you
know about boiling, boiling
water, adding salt to water,
etc.
Boiling Point Lab Report
 HYPOTHESIS:
 By examining the unknown,
take a guess as to the amount
of salt per 200 mL.
 (You can do this after you get
in lab)
Boiling Point Lab Report
 MATERIALS & EQUIPMENT:
 You can list these materials
after using them in lab
 There are a few safety
concerns which will be covered
later
What is the purpose of the Boiling Point
Lab?
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1. To heat water to the highest temperature
possible
2. To evaporate all the water from a salt water
mixture
3. To identify the amount of salt in an unknown
mixture
Boiling Point Lab Procedures
1.
2.
3.
4.
5.
6.
7.
8.
9.
Measure 200 mL of water & put it in flask
Add salt (this will vary) – 0 g FIRST TRIAL
Dissolve salt by swishing flask around
Insert thermometer & heat on hot plate
Measure temp every minute (Table 1)
Temp will stop rising at boiling point (Table 2)
Take off hot plate using flask tongs
Do not dump hot water. Let it cool.
Repeat procedure using different flask
Boiling Point Lab Safety Concerns
 Hot plates, heated glass & water may
cause severe burns – Be cautious
 Hot glass & cold glass look exactly the
same – Assume it is hot!!
 Keep cords from hanging over table to
prevent snagging and hot liquid spills
 Do not put face or any body parts
directly over flask opening
Boiling Point Lab Safety &
Equipment Concerns
 When in the same area as anyone heating
liquid, you must wear goggles (THIS IS
STATE LAW)
 Never put anything into water when it is
boiling
 Hot plates are for heating liquids only
(Any student using them improperly will
be dismissed WITHOUT warning)
Boiling Point Lab Equipment Safety
 Never expose thermometers or other
equipment to LARGE TEMPERATURE
CHANGES – especially not glass!!!
 Keep cords away from hot plate
 Use the flask tongs to remove the flask from
the hot plate (DO NOT ATTEMPT TO USE
TONGS TO DUMP OUT HOT LIQUID!!)
 Wait until the liquid cools enough to dump
out by hand
What is the purpose of the Boiling Point
Lab?
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1. To heat water to the highest temperature
possible
2. To evaporate all the water from a salt water
mixture
3. To identify the amount of salt in an unknown
mixture
How much water should go in the flask
for each trial?
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1. Fill it up
2. 100 mL
3. 200 mL
4. Doesn’t matter
How should the hot water be dumped
out?
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1.Using the lab tongs, dump it while still hot so
that it can be used immediately
2.Grab the flask by hand from the hot plate
and dump it
3.Remove the flask with tongs, set it down until
cool enough to dump by hand
Standard Lab Rules
 1.) Stay on task
 2.) Use equipment properly
 3.) Clean up after yourself
Do you understand and agree to abide by the
lab rules & procedures for personal &
equipment safety in this experiment?
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1. Yes
2. No
Boiling Point Lab
 Are you ready?
 OR
 Re-test?
What is the purpose of the Boiling Point
Lab?
0%
0%
0%
1.To heat water to the highest temperature
possible
2.To evaporate all the water from a salt water
mixture
3.To identify the amount of salt in an unknown
mixture
How much water should go in the flask
for each trial?
0%
0%
0%
0%
1. Fill it up
2. 100 mL
3. 200 mL
4. Doesn’t matter
How should the hot water be dumped
out?
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0%
0%
1.Using the lab tongs, dump it while still hot so
that it can be used immediately
2.Grab the flask by hand from the hot plate
and dump it
3.Remove the flask with tongs, set it down until
cool enough to dump by hand
Do understand and agree to abide by the lab
rules & procedures for personal & equipment
safety in this experiment?
0%
0%
1. Yes
2. No
Do understand and agree to abide by the lab
rules & procedures for personal & equipment
safety in this experiment?
0%
0%
1. Yes
2. No
Boiling Point Lab
 Finishing up the lab report
Boiling Point Lab Procedures
1.
2.
3.
4.
5.
6.
7.
8.
9.
Measure 200 mL of water & put it in flask
Add salt (this will vary) – 0 g FIRST TRIAL
Dissolve salt by swishing flask around
Insert thermometer & heat on hot plate
Measure temp every minute (Table 1)
Temp will stop rising at boiling point (Table 2)
Take off hot plate using flask tongs
Do not dump hot water. Let it cool.
Repeat procedure using different flask
Results
 Explain what the data tables and
graph show plus any other
significant observations
 Be specific as to why the data
tables & graphs were included as
well as what you learned from the
data
Table 2
Boiling Points
 Determine the temperature at
which the salt-water mixture
stopped rising.
 Record this as the boiling point
for each mixture tested.
What is the independent variable in
this experiment?
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1.Boiling Point
2.Amount of Salt
3.Temperature
4.Time
What is the dependent variable in
this experiment?
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1.Boiling Point
2.Amount of Salt
3.Temperature
4.Time
Variables
 What are some controlled
variables in this experiment?
 What are some variables that
could have been controlled
better?
Graph 1
Boiling Point vs. Amount of Salt
 Amount of salt on x-axis
 (measured in grams)
 Temperature on y-axis
 (measure in degrees Celsius)
 Plot points
 Draw line of best fit
 Determine where boiling point of
unknown intersects the line
Results
 Explain what the data tables and
graph show plus any other
significant observations
 Be specific as to why the data
tables & graphs were included as
well as what you learned from the
data
Analysis
 Be sure to share how much salt
you believe there is in the
unknown mixture.
 Be sure to mention possible
sources of error in the
experiment (variables not
controlled really well would be
great to mention here)
Approximately how much salt did you
estimate is in the unknown?
1.
2.
3.
4.
5.
6.
7.
8.
0g
5g
10 g
15 g
20 g
25 g
30 g
35 g
0%
1
2
3
4
5
6
7
8
Boiling Point Lab Report
 Finish up Lab Report
 When finished turn in or if not,
then finish ON YOUR OWN &
turn in Monday!!
Turn in your remotes