Name: ___________________________ Per: ____ Date:______________________
Chemical & Physical Changes Lab
Objective:
To observe chemical and physical changes.
To observe endothermic and exothermic changes.
To observe change in indicators when pH changes.
Note: remember observations can be anything you see, hear, smell, touch, and taste - except we don’t taste in
chemistry lab.
Materials:
zip-loc baggie
disposable cup
sodium bicarbonate (NaHCO3)
calcium chloride (CaCl2)
Procedure:
acid/base indicator(acts like water &
shows acid or base–does not react)
plastic teaspoon
Part A
1. Put ½ tsp. of sodium bicarbonate in one corner of your zip-loc bag. Record your observations of this
chemical.
2. Put ½ tsp. of calcium chloride in the opposite corner of your zip-loc bag. Do not mix the chemicals.
Record your observations of this chemical.
3. Pour about 1 mL (about ¼ of a pipet) the acid/base indicator AND 3 mL (about ¾ of a pipet) of distilled
water in the disposable cup. Record your observations of this chemical.
4. Place the cup (upright-don’t spill the liquid) into the baggie. Close the bag, trying to remove all excess
air.
5. Carefully pour the liquid into the corner with the sodium bicarbonate. Record your observations.
6. Once this reaction has completed, tip the zip-loc bag, so the liquid and sodium bicarbonate move to the
calcium chloride corner. Record your observations.
Part B
7.
8.
9.
10.
Put ½ tsp of calcium chloride in the corner of a different Ziploc bag.
Repeat steps #3 and #4 above.
Pour the liquid into the calcium chloride and record your observations.
Dispose of both bags and contents in the trash can. Wipe off your counter clean your spoon and put the
spoon back in the front of the room.
11. Remove your goggles and place in the goggle cabinet correctly.
Data Table
Chemicals
Sodium bicarbonate
Calcium chloride
acid/base indicator
Sodium bicarbonate and
indicator
Sodium bicarbonate,
indicator, & Calcium chloride
Calcium chloride and
indicator
Observations
Questions & Conclusions:
1. What is the definition of exothermic and endothermic?
Exothermic Endothermic2. Which reaction is endothermic? What proof do you have for that answer?
3. Which reaction is exothermic? What proof do you have for that answer?
4. Classify each of the reactants as solid, liquid, or gas.
Sodium bicarbonate –
Calcium chloride –
Indicator –
Water –
5. If the indicator chosen (universal) is green when it is neutral, blue when it is basic, and red when it is
acidic, did you produce an acid or base during the 5th step with sodium bicarbonate?
6. Did you produce an acid or base during the 6th step when the sodium bicarbonate and indicator were
added to the calcium chloride
7. What is the evidence that indicates that changes in the compounds have occurred?
8. What changes were chemical?
9. What changes were physical?
10. Classify the products of the reactions as solid, liquid, or gas.
11. Which combination of the starting material produces the gas?
12. Which combination of the starting material produces the acid or base?
13. Using reference materials, propose possible chemical equations for the reactions in this lab.
(Hint: Google – What do Calcium Chloride and Baking Soda make? See the ehow choice)
14. How would you test to see if these equations are correct? (consider the gas from #13 and fire )
15. Discuss any sources of error. (more than one)
Post Lab: Physical & Chemical Properties
Recall that physical properties can be observed without producing new substances. Chemical properties describe
how a substance interacts (or fails to interact) with other substances to produce new substances.
Classify each of the properties listed below as physical or chemical.
Color
Combustibility
Hardness
Density
Mass
Melting point
Ductility
Volume
Failure to react with other substances
Odor
Weight
Malleability
Tendency to corrode
1. _______________________
2. _______________________
3. _______________________
4. _______________________
5. _______________________
6. _______________________
7. _______________________
8. _______________________
9. _______________________
10. ______________________
11. ______________________
12. ______________________
13. _______________________
Chemical Reaction
Calcium chloride and baking soda react to form calcium carbonate, sodium chloride (salt), water
and carbon dioxide. To produce this reaction, calcium chloride and baking soda, which are both solid,
are mixed together in water, which provides a solvent for the chemical reaction to occur. The carbon
dioxide escapes as a fizzing or bubbling. The calcium carbonate is a white solid precipitate that sinks
to the bottom of the water. Calcium carbonate is a base and can be re-dissolved in an acid, such as

vinegar. The balanced chemical reaction is
H2O.
2 NaHCO3 + CaCl2  CaCO3 + CO2 + 2 NaCl +
Exothermic Process
The combination of calcium chloride and baking soda in water also produces heat. Because less
energy is required to break the bonds in the NaHCO3 and CaCl2 molecules than is released when the
CaCO3, NaCl , CO2 and H2O molecules form, the excess energy becomes heat and the reaction is
exothermic. The calcium chloride and baking soda reaction is a popular demonstration in elementary
and middle school science classes because of the production of heat and carbon dioxide. Because the
chemical reaction is warm and fizzy, it is interesting and safe for kids to observe by watching,
listening and touching components of the experiment. When the chemical reaction is done in a beaker
or a plastic bag, children can touch the container and feel the heat of the reaction through the glass
or plastic.

Forms of Calcium Carbonate
Calcium carbonate is produced as a white powdery solid in the reaction, and this is the form of
calcium carbonate used by some people as a home remedy antacid. Calcium carbonate also appears in

crystallized form in a number of rock structures known as calcite. Limestone is a form of calcium
carbonate, which, when it undergoes pressure, becomes marble. Calcium carbonate is also a component
of igneous or volcanic rock and is present as the cement in several types of sedimentary stone. Many
of the rock formations found in caves are created by tiny particles of calcite stone carried in water
and deposited as water flows or evaporates.
Read more: http://www.ehow.com/how-does_5498056_do-amp-baking-soda-make.html#ixzz2fq3jZM9y
OBSERVING A CHEMICAL REACTION
http://teachers.net/lessons/posts/108.html
Purpose: Students will learn to make careful observations involving chemical reactions.
Materials Needed:
Road salt (calcium chloride)
Baking soda (sodium hydrogen carbonate)
Indicator (phenol red or bromthymol blue work well)
Baggies, sandwich size (regular and ziplock)
Spatulas or plastic spoons
10 ml graduated cylinders
Procedure:
1. Put two scoops of road salt and one scoop of baking soda into a ziplock bag.
2. In another baggie (not ziplock) put 10 ml of indicator.
3. Place the baggie containing indicator inside the ziplock bag with salt and soda. Be sure the
indicator baggie is completely stuffed into the ziplock bag.
4. Carefully squeeze all air out of the ziplock bag.
5. Zip the top of the ziplock bag.
6. Invert the bag so that all contents of both bags combine. Make observations.
Discussion:
Several evidences of a chemical reaction are very apparent (color change, gas produced, heat
produced., etc.)
Make a list of all the observations you can gather. These include mass changes (if any), color
changes, temperature of materials, sounds, and any other change you may note. Make this list on
your own paper.
CALCIUM CHLORIDE: A REACTION IN A BAG. (CHEMICAL)
http://www.lessonplanspage.com/SciencePhysicalAndChemicalReactionsExperiments58.htm
Introduces students to a chemical reaction involving a color change, the formation of a gas and heat changes from hot
to cold. The students can actually hold this chemical reaction in their hands to see and feel the reaction take place.
The acid-base indicator will change colors (from basic to acidic). For example: phenol red solution goes from red to
orange to yellow. Universal indicator solution starts out green and changes to pink. Cabbage juice, changes from bluegreen to purple to pink. The plastic bag will also inflate due to the formation of carbon dioxide gas.
You will need:calcium chloride, Sodium Bicarbonate (baking soda), Acid-Base indicator (any kind), Ziplock sandwich
bags, spoons, graduated cylinder
1. Place one spoonful of calcium chloride into a plastic sealable bag.
2. place 1 spoonful of sodium bicarbonate (BAKING SODA) into the bag. Seal the bag, shake it and see if a chemical
reaction takes place.
3. measure 10 ml (or 2 teaspoons) of indicator solution. Carefully add it to the bag. Flatten the bag to remove the air
and seal it.
4. Tilt the bag back-and-forth to wet all of the solid. Squeezing the bag may also help in wetting the solid. Be careful
not to squeeze the bag too hard as it might break or open up.
5. observe the reaction. If the bag gets tight due to pressure, open the seal to release the pressure, then reseal it.
6. Answer the following:
a.) How was this experiment different then the one before?
b.) Did a noticeable reaction occur before the indicator solution was added?
c.) What color change did the indicator go through?
d.) Why does the bag inflate?
e.) Does the reaction get hot or cold initially?
f.) Does the reaction get hot or cold after 1 minute?
g.) What observations did you make that tell you a chemical reaction is taking place?
h.) Was this experiment a physical or chemical reaction?