Boiling Point Lab

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


BACKGROUND INFO: List and describe details you

know about boiling, boiling water, adding salt to water,

etc.


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)


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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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

Boiling Point Lab Procedures

1. Measure 200 mL of water & put it in flask2. Add salt (this will vary) – 0 g FIRST TRIAL3. Dissolve salt by swishing flask around4. Insert thermometer & heat on hot plate5. Measure temp every minute (Table 1)6. Temp will stop rising at boiling point (Table

2)7. Take off hot plate using flask tongs8. Do not dump hot water. Let it cool.9. 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


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?

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0%

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0% 1.Fill it up2.100 mL3.200 mL4.Doesn’t matter

How should the hot water be dumped out?

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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

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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0% 1.Yes2.No

Boiling Point Lab Are you ready?

OR Re-test?


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 up2.100 mL3.200 mL4.Doesn’t matter

How should the hot water be dumped out?

0%

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.Yes2.No

Do understand and agree to abide by the lab rules & procedures for personal & equipment

safety in this experiment?

0%

0% 1.Yes2.No

Boiling Point Lab Finishing up the lab report

Boiling Point Lab Procedures

1. Measure 200 mL of water & put it in flask2. Add salt (this will vary) – 0 g FIRST TRIAL3. Dissolve salt by swishing flask around4. Insert thermometer & heat on hot plate5. Measure temp every minute (Table 1)6. Temp will stop rising at boiling point (Table

2)7. Take off hot plate using flask tongs8. Do not dump hot water. Let it cool.9. 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 2Boiling 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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0% 1.Boiling Point2.Amount of Salt3.Temperature4.Time

What is the dependent variable in this experiment?

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0% 1.Boiling Point2.Amount of Salt3.Temperature4.Time

Variables What are some controlled variables in this experiment? What are some variables

that could have been controlled better?

Graph 1Boiling 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?

0%0%0%0%0%0%0%0%

1 2 3 4 5 6 7 8

1. 0 g2. 5 g3. 10 g4. 15 g5. 20 g6. 25 g7. 30 g8. 35 g


Finish up Lab Report When finished turn in or if not,

then finish ON YOUR OWN & turn in Monday!!

Turn in your remotes

Documents

Boiling Point Lab