Chart 1: Qualitative Observations
Test | A | B | C | D | E | Mystery X | Mystery Z |
Appearance | Pure white tiny grains
Looks like salt
|
Shiny rough white crystals
Looks like sugar |
Powdery pure white molds together but not that well
reminds me of cornstarch |
Its powdery and it can easily mold together its white and It looks like whole wheat flower | small Grainy Pure white and is powdery | Thin pure white powder that molds together a little bit | It’s a mix between powdery and grainy its like soft sand |
Dissolves in Water
|
It dissolves in the water a little bit | It dissolves in the water | It sat above the water and slowly sank in it became thick | I sat above and slowly sank in it became squishy | It dissolved | It became hard
|
It became watery |
Heated in Aluminum foil
|
Stayed the same | It first change color to a light brown and started to boil then when it cooled down it became hard like a rock | It burned | It turn a beige but didn’t burn not as bad has some other ones | Stayed the same | Stayed the same | Stayed the same |
Universal Indicator
|
It became yellow and orange with red dots | It became mostly red and the outside yellow | It became orange and it absorbed the indicator | It became yellow | It became a dark green with a hint of yellow | It became light green with I tiny bit of yellow | It became yellow and sank into the substance |
Iodine Solution
|
It seeped through fast | It seeped through fast | It sat above the power and ate away at it made the color brown
Hard goo |
It sat above than slowly seep in and has a little bit of foam | It seeped in fasted | It seeped in slowly and changed the color brown | It sat above for the longest and turned a little bit brown it became hard |
Vinegar
|
It just absorbed it | It absorbed it | It became a hard and thick substance | It became gooey thick | It raised and bubbled | It raised and bubbled | Became soft and foamy |
Chart 2: Identifying Chemical and Physical Changes
Test | A | B | C | D | E | Mystery X | Mystery Z |
Dissolves in Water
|
p | p | c | c | p | p | p |
Heated in Aluminum foil | P | p | c | ||||
Universal Indicator
|
c | c | c | c | c | c | C |
Iodine Solution
|
p | p | C | C | p | C | C |
Vinegar
|
p | p | c | c | c | c | c |
- Explain the difference between a chemical and physical change.
The difference between a chemical and physical change, is chemical change is when an object is mixed or made into a new material or structure, for example when you add vinegar to baking soda it is a chemical change because you are adding a substance to the original matter. Physical change is when the matter looks different but didn’t change the product or didn’t add a chemical to it. For example when you take ice out of the freezer and melts, it changes physically because it looks different, but if you put it back in the freezer it turns back into ice, or when you break your mug it physically looks different but the material of the mug stayed the same. So the difference is a chemical change is when you add a new chemical and is changes product or structure and a physical change is when it looks different but it is still the same thing.
- For unknown D, explain the results of each test, including what you saw and whether what you saw was a chemical or physical change.
The appearance before I did any testing was a powder like substance and the powder was easily moldable, the colour of unknown D was white with a slightest tinge of brown. In my opinion and others it look like whole wheat flour because of the texture and the tinge of brown. The dissolves in water test showed that the powder was dense because the water didn’t sink in for a while, once it sank in unknown D became squishy. For if it dissolves in water, I said it was a chemical change because the powder became squishy and you can’t reverse the change. For the heating in Aluminum unknown D turned a beige colour, after a while it started to burn, but not as bad as some of the other matters. I said from that test D did a chemical change because when you burn something you can’t reverse it, like when wood burns and it makes ash you can’t turn ash back into wood. The universal indicator test made unknown D change its colour from whiteish brown to yellow, that means it’s a chemical change because it occurs that there was some kind of reaction that happen to make the colour change. Unknown D reacted to the Iodine Solution by foaming up a tiny bit and unknown D also kept the Iodine Solution from seeping in for a little bit. Unknown D got a chemical reaction because it started to foam up when I poured the Iodine Solution, it’s a chemical change because you can’t change what happens to the powder. The vinegar test showed that it was a chemical change because the powder turned into thick goo like Oobleck which makes it a chemical change because you can’t reverse goo into powder. Unknown D had all chemical changes.
- Based on your results identify which two powders make up Mystery Powder X and which two powders make up Mystery Powder Z?
Based on my results I think the two substance that make up X was D and A because A had a tiny grain like texture like salt and the colour was pure white. D had a powder texture and D is the same colour as X. In my opinion X has a mix of those characteristics because X has thin powder that barely molds together and it’s probably the grains from A stopping it from molding that well. Based on my results I think the two substances that make up Z is C and E because C is a pure white powder that does mold that well and E has small grains and is powdery. Z has the texture of a mix between powdery and thin grains it reminds me of soft sand, in my opinion its colour is a mix of C and E. That why I think X is D and A mixed and Z is C and E mixed.
- Explain any experimental sources of error from this lab (where could you have possibly made a mistake?)
A source of error I made was that I blew on the dish, to get the powder off the sides of it and all the rest of the powder on the dish went on my face when I should have just brushed it off. I also made a mistake when I sat on the counter beside the burner, well I was watching it but I was nicely reminded that I should get off and I won’t do it again because I now relieze how it was dangerous.