i need pre lab and post lab from document 5, now send me pre lab, when i get the data you do post lab.
Post-lab
5
Title: Unknown Salt by Determination of the Percentage Copper.
Name: Sixto Sanchez
Date:
2
/28/2022
Unknown:
Purpose: The purpose of the experiment is to identify an unknown salt by determining the mass percentage of copper in the salt.
Balanced Equations:
Cu
3
(PO
4
)2 • 3H2O
+Z Zn3PO4 + Cu + H2O
Zn +H2SO4 ZnSO4 +H2
Table of Chemical and Physical Properties:
Chemical Name
Molecular weight
Boiling Point
Density
Safety
Copper (II) phosphate Trihydrate
434.
6
266 g/mol
1
58ºC
434.627 g/mol
Irritant, avoid contact with eyes
Copper (II) chloride dihydrate
170.48256 g/mol
993 °C
3.386 g/cm3
Irritant, avoid contact with eyes, skin.
Avoid ingestion.
Inhalation
Copper sulfate pentahydrate
156.609 g/mol
330 °C
3.60 g/cm3
Irritant, Causes nausea, headache.
Copper (II) Perchlorate Hexahydrate
370.538 g/mol
120 °C
2.25g/cm3
Corrosive, Irritant, toxic
Copper (II)Selenate Pentahydrate
296.58 g/mol
330 °C
2.286 g/cm3
Corrosive, irritant
Copper (II) acetate monohydrate
199.6493g/mol
240 °C
1.882 g/cm3
Irritant, avoid contact with eyes and skin
Deionized water
18.015 g/mol
100 oC
1.000 g/cm3
Irritant. Do not inhale or ingest
Zinc
65.38 g/mol
907 oC
7.133 g/cm3
Irritant.
sulfuric acid
98.079 g/mol
337 oC
1.84 g/cm3
Corrosive. Avoid direct contact with eyes, nose, throat, and upper airways
Sample Data Table for Percent Copper in Reactants:
No. |
The formula of Copper Salt |
IUPAC Name |
Molar Mass (g/mol) |
Percent Copper |
1 | Cu3(PO4)2 • 3H2O |
43.8625% |
||
2 |
CuCl2 • 2H2O |
37.274% |
||
3 |
CuSO4 • 5H2O |
25.450% |
||
4 |
Cu (ClO4)2 • 6H2O |
17.1496 % |
||
5 |
CuSeO4 • 5H2O |
25.47% |
||
6 |
Cu (CH3CO2)2 • H2O |
31.8288% |
Procedure |
Observation |
1. Weigh 1g of unknown copper salt, record the unknown number and the color of the salt. 2. Transfer the unknown copper slat into a 100mL beaker. 3. By using a 100 mL cylinder, obtain 30 ml of deionized water and add it to the beaker containing the unknown copper salt. 4. Heat the solution gently to dissolve the salt. 5. Weigh out 1g of mossy zinc and add to the solution 6. continue with heating the solution until the solution color fades. 7. Add 0.3 g f zinc if the color remains. 8. After the solution is completely colorless, stop heating and allow it to cool. 9. Collect all copper in a filter 10. Ad 1.5mL of sulphuric acid to approximately 15mL of deionized water and rinse collected copper to ensure zinc has been eliminated 11. Following the addition of the acid rinse, wash thoroughly with copious amounts of deionized water After draining the filter paper from the last rinse, transfer filter paper with contents onto the pre-weighed watch glass. 12. place the sample into a steam bath and allow it to dry for at least 20 minutes. 13. Once it has dried, remove it from the oven and allow it to cool to room temperature, and obtain the mass of the sample. |
The observations are documented on the data table below |
Data collected
Observations |
|
Reacting unknown salt |
No physical change is observed after reacting with 1g deionized water. |
Adding Zinc in the solution. |
Reddish-blown substance is formed. |
Zinc elimination, reaction with Sulphuric acid. |
A colorless gas is produced which burns with a pop sound. |
Sample Data Table:
a) Unknown number/letter of copper salt: ___Al_____
b) Mass of unknown copper salt in grams: __1 g ______
c) Mass of mossy zinc in grams: ____1.01 g +_0.34g____
d) Mass of watch glass + filter paper in grams: ___28.93g_____
e) Mass of watch glass + filter paper + copper in grams: __29.41______
f) Mass of copper in grams (e – d): ____0.48 g____
g) Experimental percent copper in salt (f/b X 100%): _____48 %_____
h) Identity of copper salt based on percent copper: Cu3(PO4)2.3H2O
i) Balanced equation for the reaction: Cu3(PO4)2.3H2O + Zn Zn3PO4 + Cu +H2O
j) Balanced equation for zinc elimination: Zn + H2SO4 ZnSO4 +H2
Discussion
In this lab, physical and chemical properties are observed. For instance, after adding Zinc to the solution of unknown Copper salt, a reddish-brown substance is formed, which is copper metal. This is due to the high reactivity of Zinc which leads to copper being replaced from the salt. Also, during the elimination of Zinc, a colorless gas was produced that produced a pop sound when burned.
Conclusion
Certain chemicals react more than others. Due to this reason, it is possible to recognize physical and chemical changes when the chemicals are mixed. By comparing the percentage of copper obtained from the experiment with the percentage of copper contained in various copper salts, the unknown salt is likely to be Copper (II) phosphate Trihydrate.
Date Completed & Signature