Date of experiment: 9/16/2014
Date of submission: 9/23/2014
Experiment # 3
Purpose: the purpose of this experiment was to explore the distinctions between physical and chemical properties and between physical and chemical changes.
1. Based on my observation CaCl2 is soluble in water.
2. When 15% of HCl was added to CaCl2 as the teacher was performing the experiment I observed and realized some changes took place physically. It was physical change because the color was clear.
3. By adding 15% of HCl of CaCo3 , made it change chemically, I would tell this by effervescence and observation.
4. The most obvious difference is that when CaCl2 was mixed with 15% HCl it changed physically and the solid remain on the filter paper is CaCo3 reacted to 15% it changed chemically.
5. Based on my preliminary investigation I would say that CaCl2 is dissolving and CaCo3 is not dissolving in water, as we can see the colorless water in filtrate.
6. Yes, we would separate it by boiling the water off to prove the hypothesis.
7. The solid remain on the filter paper is CaCo3, because it did not dissolve in water.
8. I would expect to see a dry CaCo3. The water will boil and dry off.
9. My answer is to question 7 is consistent with the observations at this step because effervescence occurred which means that CaCo3 was not dissolved, it was left over in the filter paper.
10. Based on my observation I think Residue A is not the same substance because when I added to filter paper it bubbled but when I added to residue A It didn’t react.
11. No, because the color of residue B changed after it was mixed with 10 drops of 15% HCl.
12. I think it was chemical because it’s not the same anymore, also effervescence occurred, when HCl was mixed with residue B.
13. At step 9 CaCl2 was separated from the CaCO3.
14. The hot plate makes iodine hot while ice cubes keeps the dish cool.
15. It is going under physical