Discussion/Analysis 1. a) The physical properties that I examined in this experiment are state (at room temperature), colour, clarity, and crystal shape. b) The chemical properties that I examined in this experiment are reactivity in water and in acid. 2. Sample #1 is baking soda. This is because like the other samples baking soda was a solid and it was white. It was also opaque and in power form just like sample #4. What makes baking soda different from sample #4 is it was soluble and when acid was added, it fizzed and dissolved quickly. Sample #2 is sodium thiosulphate. This is because the behaviour of this substance in acid is it turns cloudy yellow. Although, my observations interrupt the crystal shape of being small cubes, the shape turns …show more content…
The property that was the most helpful in identifying the solids was the behaviour of the samples in acid. This is because all of the samples had different behaviours when acid was added with the exception of sodium and sodium nitrate. This was also the most helpful because most of the properties were the same for most if not all the samples. For example the state and colour of the samples; they are the same for all the …show more content…
I feel confident about my identifications because my observations match the properties list given on the lab instruction (Table 1). Some of them were easy to figure out like sodium thiosulfate. This is because this was the only sample that turns cloudy yellow when acid is added to it. There were a couple of properties that gave away the identification of certain samples. The most difficult substances to identify were salt and sodium nitrate. For me this is because before looking at each sample under magnifying glass, salt and sodium nitrate looked the same. Also, the other properties matched each other so they only way to find the difference was to carefully examine each substance. After, carefully examining each sample the difference between them was seen. So then, I was able to identify
We were assigned mystery powder convertible which contained calcium carbonate, baking soda, and sucrose. We found out that the mystery powder had calcium carbonate because when it reacted with iodine it turned orange/brown. When calcium carbonate reacted with vinegar it had a fizzy-like reaction. It also reacted with hydrochloric acid and that caused it to bubble. When we tested the mystery powder it also turned orange/brown when we added iodine. Also when we added vinegar and it also fizzed like the calcium carbonate. Again when we added the hydrochloric acid it reacted exactly like calcium carbonate, lots of bubbles were made. We know that the calcium carbonate was in the mystery powder because it had similar reactions.
Formoso, M. (2013). Acid Test: How to tell Minerals Apart . Retrieved January 13, 2014, from Education.com : http://www.education.com/science-fair/article/Acid-Test-How-Minerals-Apart/
4. The melting points of the solids were tested by placing them in crucibles and heating them using a hot plate.
The problem that was trying to be solved in this study deals with analyzing unknown solutions. In this particular case, a chemical company has several unknown solutions and to correctly dispose of them they need to know their properties. To figure out the properties several qualitative tests were performed throughout the study (Cooper 2012).
3. Examine the luster of the minerals in Figure 1.2 (p. 4 lab book). Place the letter A, B, C, D, or E in
You find a sample of a solution that has a faint odor resembling vinegar. You are verifying that it is indeed vinegar and you add a few drops of phenolphthalein. The sample turns pink. What assumptions can you make about this sample?
The goal of the experiment was to identify Unknown 33A and 33B. Unknown 33A was a white, crystalline solid that had a sweet cherry smell and Unknown 33B was a beige, yellowish color liquid that was translucent and had a viscosity similar to water. Also, the liquid was homogenous and smelled sour, similar to mildew.
Purpose: The purpose of this experiment is to observe a variety of chemical reactions and to identify patterns in the conversion of reactants into products.
b) Observe and record data in the data table on its state of matter, appearance, and texture and whether it has a crystalline structure.
The primary goal of this laboratory is to correctly identify an unknown substance. To achieve this task, one may use various tests that reveal both chemical and physical properties of a substance. By comparing the results of a known substance and the unknown substance, one may eliminate alternative possibilities and more accurately predict the undisclosed compound. Furthermore, by performing these tests, data can be collected and verified regarding chemical and physical properties of the unknown. Understanding the chemical properties of a known substance aids one’s understanding of the unknown based on comparative analysis of the results of the tests.
Counterclaim:I disagree with the other group that thinks it's baking soda,citric acid, epsom salt. I disagree with them cause me and my partner tested both thoughts of each group. The first thing me and my partner did was put it in a well tray and put water in it. Then we tested the temperature the mystery mixture was 15.9, baking soda and citric acid was 16.2 degrees Fahrenheit, and baking soda citric acid and epsom salt was 16.8. After we did this we put 10 drops of water in them and left them overnight. When we came back the next morning we looked and they all turned to a crystal looking thing on the bottom of the well tray they were all white but baking soda, citric acid and epsom salt looked a little different because at the bottom it had more white color. But for baking soda and citric acid it left barely any color just like the mystery mixture. That is why I disagree with baking soda, citric acid and epsom salt.
In the last test, we had to test out a mystery powder (powder A, B, C), in its own separate test tube, in order to solve the Sherlock Holmes Mystery. Our group had powder C. When we mixed water in the mystery powder, it did not dissolve. When the litmus paper was put into the test tube it turned blue. When the vinegar was mixed it bubbled/foamed up. When we mixed the iodine solution, there was no reaction and the solution turned to a dark brown/black color. When we mixed in the baking soda there was no reaction and it turned to an even darker color.
The composition of a pure substance is constant, and thus pure substances have characteristic physical properties that do not change and this is why we are able to separate each element in this lab experiment. Examples of physical properties that can be used to describe pure substances include solubility, conductivity, magnetism, density, boiling point, and melting point.
The main objective of this experiment is to differentiate between a physical change and a chemical change.
Product bubbled upon addition to the hydrochloric acid; liquid turned cloudy ¡V precipitate was present; zinc sample disintegrated slowly and turned black in color.