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!!!!

2. 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.  

 

1. White, solid, room temperature, powder, 

 

 

What is it’s formula?

NaHCO3

 

 

List some of the uses of this chemicals?

 

Baking 

 

 

2. 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.  
3. It’s round, white, solid 

What is it’s formula?

CaCI2

List some of the uses of this chemicals?

 

To treat severe calcium deficiency 

3. How is chemical B different from Chemical A?
5. Chemical a is rounder, bigger, and denser. 
7. Look and describe Chemical C (Bromothymol blue).  Record your observations in the space provided below. 
8. Liquid, blue, 

 

What is it’s formula?

C27H28Br2O5S

 

List some of the uses of this chemicals?

 

It dyes stuff

 

Now you are ready for the observations of change. 

1. Mix a small amount, not all of it, Chemical A with Chemical B in the middle zip-lock bag.  Record observations.  
3. Nothing changed, it’s all mixed together. No chemical reactions. 
10. 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.

 

It turned yellow, created gas, and turned into a clumpy substance.  

 

 

 

1. Detect any temperature changes with your hand.
2. It got really warm and then really cold. 
6. After 2 minutes thoroughly record any new observations.

1. It has reduced to a chunky substance and released a lot of air. 
4. In the space below add at least two photographs of your zip-lock bag.

 

 

 

1. 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.

 

1. What evidence of chemical change did you observe in the bag? 
3. The chemicals were bubbling up. 
4. What physical changes did you see? Answer in complete sentences.  

 

 It went from a powder to a bubbly, yellow, liquid substance, it released a ton of gas. Then it turned into a yellow chunky paste and the bag was filled with air.