Engel’s earth science on a shoestring Simonized©
Materials for the Lab-
Name______________________
Date _____________
Hr____
Graduated cylinder, calculators, thermometer, colored pencils, scale, salt, salt water, empty cup,
Acetic acid,(vinegar) Graduated cylinder, electronic scale, permanent marker.
Procedure 1: QUESTION: What does density have to do with floating?
Calculating the density of Saltwater
Step 1-Place one plastic cup on the scale and turn it on. (Tare it) The scale should now read “0”. Pour
100 ml of tap water into a beaker. Pour it into the cup. Record the mass here_________ Calculate the
density of fresh water. (D=m/v) Record the density here_________
Step 2- Empty the fresh water into another group member’s plastic cup. Place another group member’s
plastic cup into the big aquarium and let if sink to the bottom. Have the instructor retrieve the cup from the
very bottom of the tank and pour 100 ml of this salt water into a graduated cylinder. Then take back to your
lab desk and pour 100 ml of saltwater into a plastic cup. Add dye to the salt water and stir in. Record the
mass here_________ Calculate (D=m/v) the density of salt water.____________g/cm3 which has more
density, fresh or salt water? _____________
Procedure 2: Finding out how thermohaline currents work
Step 1- Take a group member plastic cup and let is sink to the bottom of the saltwater tank and then
GENTLY scoop up at least half a cup of salt water from the bottom.
Step 3- Fill the glass half full with fresh tap water from the sink.
Step 4- Slowly pour the colored salt water into the glass using the following technique. Dribble the salt
water down the edge of the freshwater cup and let it slowly sink to the bottom of the glass. Have all
members place the heads on the table as you slowly pour the colored saltwater
down the side of the cup. Using colored pencils draw in the cup to the right what
happened as the saltwater was slowly poured down the side of the glass into the
fresh tap water.
Step 5- Describe what happened as the saltwater was slowly poured down the
side of the cup containing the fresh tap water._____________________________
Procedure 3: Calculating the density of an egg
Step 1- From the lab area get an egg for each member of the group and gently place it into your empty
lab basket. Please be careful in transporting the eggs as they are raw.
Step 2- Have each member choose and egg and using the permanent marker place his/her name on the
egg. Leave space on the egg as many other things will be recorded.
Step 3- Mass each of the eggs separately.
Place one plastic cup on the scale and turn it on. (Tare it) The
scale should now read “0”. Now you can place the egg on the scale and record the mass of the egg in Table
2 and on the egg shell with the permanent marker.
More needed information:
Due to the shape of the egg we will use water displacement, Archimedes style. Archimedes principle,
which states that a body placed in water, will displace an amount of water, which weighs as much as
the object would weigh in air.
Step 4- Use an overflow beaker like when we found the density of rocks in the mineral unit to find the
volume of each egg. Place the overflow beaker near the edge of the lab table and have one lab member fill
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the overflow beaker with fresh water until the beaker overflows into a graduated cylinder held by below the
out flow spout by another lab group member. When it stops dripping into the cylinder, it is ready for the
egg.
Step 5- Carefully grip the egg by the skinny end and GENTLY lower it into the overflow beaker fat end
first lower it as far as possible before letting go..
Steps 6-Collect the water in the graduated cylinder, as soon as the overflow beaker stops dripping you
may wish to yell Eureka! … (But keep your clothes on!)
Step 7- Record this value in table # 2
REPEAT STEPS 4-9 FOR EVERY EGG AT YOUR LAB TABLE.
TABLE #2
EGGCITING INFORMATION
NAME
MASS (g)
VOLUME (ml)
DENSITY (g/cm3)
Key ideas:
Evaporation makes water more saline and denser
Freezing makes water more saline and denser
Cold water is denser than warm water
Procedure 4: why are the oceans layered?
(Or why does ocean crust eventually sink back into the
mantle?)
More information needed for the lab:
Things sink until they float. (They encounter a layer below them that is denser than the object
sinking.) If an object is denser than the solution it is in, the object will sink. If the object is less dense than
the solution it is in, it will float on top of the layer. Your goal in this procedure will be to, as a group, get
one of your eggs to hover. Hover is defined as “the act of being suspended in air or in saltwater”, not
sinking or rising.
Step 1-Using your knowledge of density and how things float or sink get one of the eggs of your lab
group to hover. You will use a beaker, an egg, saltwater and fresh tap water.
Step 2- Call instructor over to your table when you are able to hover an egg.
A hovering egg is not
sticking out of the water on top, and is not touching the bottom of the beaker. It splits the two layers
Step 3-Explain the process you used to get your egg to hover.
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Procedure 5- Preparing your egg for another exciting lab next week.
Step 1-Place your egg in the plastic cup with your name on it.
Step 2- Using the permanent marker, write your name and hour on the outside of the cup.
Step 3- Pour acetic acid, vinegar, over your egg until it is covered. The acid will act like carbonic acid
falling on limestone.
Step 4- Observe your egg for 7 minutes.
Take it
out of the vinegar every 2 minutes and wipe the
surface of the egg, what do you observe? _____
_______________________________________
_______________________________________
Step 5- Place your frosty cup with egg and
vinegar in the designated lab desk cabinet until next
week.
Procedure 6Question: Do the five layers of the atmosphere have weight?
Read the entire egg lab part 7 procedures before beginning the experiment.
Step 1- Place the flask in the center of the lab table, and tear out the matches out of the match book, by
ripping the book in half as shown by your instructor. Bundle them together.
Step 2-Have each group member removes one egg at a time from the cup and note any changes in the
egg or vinegar in the observations area of the lab. Have the cup owner hold the egg near the opening of the
flask. Place flask on a pad of note paper or student folder.
Step 3-BEFORE YOU LIGHT A MATCH, PUT ON YOUR SAFETY GOGGLES!
Remove one more
match from the book and light it. Rest the match bundle on the edge of the flask over the opening, and have
another lab member light the bundle of matches FROM THE BOTTOM! As soon as the match bundle
begins to burn, drop the bundle into the flask, and within one second, place the egg into the opening of the
flask skinny / pointy side down. Have each group member repeat this step.
Step 4 When you dropped the burning matches into the flask, the air heated up. Hot air is moving faster
and takes up more space. Hot air is less dense than cool air and it rises up and out of the flask. As the
matches burning in the flask go out, the air in the flask cools it becomes denser and takes up less space.
Cool air sinks because it is more dense. The egg is pushed into the bottle by the air molecules outside of the
flask. Remember, in science things push, the pull but never does science ever suck. There is no such thing as
a sucking force. The lack of air molecules cause the egg to enter the flask being pushed in from the air
molecules on the outside of the flask. The egg may even explode near the bottom of the flask due to the near
total lack of air molecules inside the flask.
If the chemical formula for egg shell is calcium carbonate or CaCO3 and the chemical formula for Acetic
Acid is CH3COOH, what might the gas bubbles on the shell of the egg be? ___________________ (What
gas is given off by Limestone when it dissolves?) Why are people so concerned about the acidification of
the environment? ______________________________________________________________________
____________________________________________________________________________________
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Think about the affect of acid rain on limestone and what if the oceans became as acidic as pop? (Fizzy
too!;-)
Before you do the post lab questions, check out these
websites!
http://www.goodearthgraphics.com/virtual_tube/virtube.html
http://www.authorstream.com/presentation/Marigold-60323-03-OceanCirculation-SOAR-2005-Coriolis-Force-Energy-Transfer-Properties-Water-oceancirculaEducation-ppt-powerpoint/
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