PREFACE:
In this lab activity, you will mix 3 unknown substances together in a bag and observe the changes that occur. There will be both chemical changes and physical changes. Observation skills are crucial for this lab investigation. Watch for changes in state (solid, liquid, gas), colour (use noun-colour description), volume (mL), temperature, and anything else you can detect. Do not smell any of this substances please.
MATERIALS: PLEASE NOTE WHMIS LABELS AND ACCORDING SAFETY
Chemical A (a white solid)
Chemical B (a white solid)
Chemical C (a blue liquid)
50 mL graduated cylinders
Plastic bag
goggles
PROCEDURES:
GOGGLES ARE DONNED
& NOT REMOVED UNTIL EVERYONE’S LAB CONCLUSION!!!!
Add one spoonful of Chemical A (sodium bicarbonate) on the left side of the zip-lock bag. Describe and record the properties for Chemical A.
What is it’s formula?
NaHCO3
List some of the uses of this chemicals?
Cooking, tooth paste
Add 1 spoonful of Chemical B (Calcium chloride) on the right side of the zip-lock bag. Do not mix the chemicals. Describe and record the properties for Chemical B.
small white pebbles
What is it’s formula?
CaCI2
List some of the uses of this chemicals?
plastics, wastewater treatment plants, in blast furnaces
How is chemical B different from Chemical A?
Chemical B is the size of a pebble and Chemical A is a powder
Look and describe Chemical C (Bromothymol blue). Record your observations in the space provided below.
What is it’s formula?
C27H28Br2O5S
List some of the uses of this chemicals?
testing pH and for testing photosynthesis and respiration
and To measure the presence of carbonic acid in a liquid.
Now you are ready for the observations of change.
Mix a small amount, not all of it, Chemical A with Chemical B in the middle zip-lock bag. Record observations.
Chemical A and B don’t show any changes when mixed
Add 10 mL of chemical C into a plastic bag. QUICKLY remove as much air as possible and then seal it up. In the first 30 seconds, squeeze the bag in various places to mix the chemicals. What do you observe? Take a photograph and if possible video recording.
cm-chat-media-video-1_ca7e559d-436e-5176-85f5-34512a2a357e_13_0_0 (1)
Detect any temperature changes with your hand.
It’s a little warm
After 2 minutes thoroughly record any new observations.
It seemed to produce a gas
In the space below add at least two photographs of your zip-lock bag.
When you are finished, wash all the chemicals down the drain and rinse out the plastic bag. Discard the UNSEALED bag in the correct discard. DO NOT take off your goggles until everyone in the room has completed the lab.
What evidence of chemical change did you observe in the bag?
It produced a gas and filled up the bag like a balloon
What physical changes did you see? Answer in complete sentences.
A physical change that I saw, was that it become a thick liquid and dissolved most of chemical B.
POST THIS LAB ON YOUR EDUBLOG
BE SURE TO INCLUDE YOUR VIDEO IF POSSIBLE!!