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?
This formula is called NaHCO3.
List some of the uses of this chemicals?
This chemical is used for cooking , cleaning and for neutralizing acids.
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.
What is it’s formula?
This formula is called CaC12.
List some of the uses of these chemicals?
It is used as a food additive, food preservation, de-icing roads, and used in pool chemicals.
How is chemical B different from Chemical A?
Chemicals A is smooth and chemical B is made of small balls. They are also used for different uses.
Look and describe Chemical C (Bromothymol blue). Record your observations in the space provided.
What is it’s formula?
The formula is called C27H28Br2O5S.
List some of the uses of these chemicals?
Bromothymol blue may be used for observing photosynthetic activities, or as a respiratory indicator.
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.
When mixing chemical A and B in the zip lock bag they did mix although there was no change in their physical form.
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.
Immediately when chemical C was added into the bag the colour turned from blue to yellow, the powder started foaming and the temperature turned hot.
Before After
After 2 minutes thoroughly record any new observations.
After 2 minutes the temperature changed to a cooler temperature, the powder had stopped foaming, the bag had filled up with air/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?
The temperatures differed from hot to cold multiple times. The powder
Had changed textures, the chemicals were mixed and there was air/gas released into the bag.
What physical changes did you see? Answer in complete sentences.
The physical changes that we saw were that the colour of the chemicals that we were using had changed from the white powder and the blue die to the whole thing going a gold yellow colour. When we added in the blue die it made the powder foam.