CH 204 – Introduction to Chemical Practice Experiment #1 – Qualitative Analysis of Cations Anam Zaki* Baylee Halliwell TA: Jiawei (Will) He February 16, 2016 RESULTS & DISCUSSION The purpose of this experiment was to use qualitative analysis in order to identify two cation in a solution. During the first part of the experiment, the identity of either silver or lead was revealed, and during the second part, the identity of either calcium or barium was discovered. For the last part of the experiment, many different cations were exposed when Cation Flame Tests were executed. A wooden stick dipped into each solution and was held over a flame, and the color of the flame revealed the cation that was in the solution. For the first part of …show more content…
Hydrochloric acid, HCl, reacted with the cation, Ag+, to form AgCl(s) and H2(g). The AgCl(s) formed was the precipitate that settled towards the bottom of the test tube. The liquid was discarded and 4 ml deionized water was added to the precipitate and was heated in a bath of boiling water. This was done so that if lead were present in the precipitate, it would mix with water because lead chloride is soluble in hot water. Lead would be in the liquid part of the solution instead of staying in the solid precipitate form. In the second part of the experiment, potassium chromate, K2CrO4, was mixed into a solution to test whether or not barium was present in the solution. If barium was present, then the negatively charged chromate anion would have reacted with barium to form a yellow precipitate, BaCrO4. In step 12, a false positive could have occurred. The OJP Drug Court Clearinghouse and Technical Assistance Project describes a false positive as a result that would not be proven if further tests were performed.1 If a precipitate was formed, and it tuned into a white precipitate after step 13, it is still necessary to perform step 14. This is because if a white precipitate is formed after step 14, then the solution contains calcium. It was important to perform step 14 because barium could have been incorrectly identified. If …show more content…
Silver: Formula Unit:[Ag(〖NH_3)〗_2 ]Cl_((aq))+2H〖NO_3〗_((aq))→AgCl_((s))+2NH_4 〖NO_3〗_((aq)) Total Ionic Equation:〖Ag^+〗_((aq))+〖〖〖2NO〗_3〗^-〗_((aq))+〖2H^+〗_((aq) )+〖Cl^-〗_((aq))→AgCl_((s))+2N〖〖H_4〗^+〗_((aq))+2〖〖NO_3〗^-〗_((aq)) Net Ionic Equation:〖Ag^+〗_((aq))+〖Cl^-〗_((aq))→AgCl_((s)) Calcium: Formula Unit: Ca(〖〖OH)〗_2〗_((aq) )+〖K_2 C_2 O_4〗_((aq) )→〖CaC_2 O_4〗_((s) )+2KOH_((aq)) Total Ionic Equation: 〖Ca^(2+)〗_((aq))+O〖H^-〗_((aq) )+〖K^+〗_((aq) )+〖〖C_2 O_4〗^(2-)〗_((aq))→〖CaC_2 O_4〗_((s))+2〖K^+〗_((aq))+2〖OH^-〗_((aq)) Net Ionic Equation: C〖a^(2+)〗_((aq))+〖〖C_2 O_4〗^(2-)〗_((aq))→C〖aC_2 O_4〗_((s)) REFERENCES Drug Testing in a Drug Court Environment: Common Issues to Address. https://www.ncjrs.gov/pdffiles1/ojp/181103.pdf (accessed Feb. 14, 2016). Dogancay, D. Flame Tests Performed Safely: A Safe and Effective Alternative to the Traditional Flame Test. Sci Teach [Online] 2005, 72,
We then proceeded in testing for excess Ca2+ by adding two drops of .5 M K2C2O4 to test tube two and attentively observed to see if a precipitate formed, which it did. This meant that Ca2+ was in excess and C2O42- was the limiting reactant in the original salt mixture. We then cleaned up. Upon returning to our next class, we took the filter paper, with the precipitate on it, and took its mass.
= = == Calcium Carbonate + Hydrochloric Acid Calcium Chloride + Water + Carbon Dioxide Equipment ---------
Results: After the first two days, there were no results as I expected. Once the third day arrived, I checked at about 2:00 p.m. and noticed a slight stem coming from a few of the beans that were placed outside in the sunlight. That made my results clear that bean seeds germinate fastest outside with the sun shining down upon them. The fourth day brought more growth to the ones outside in the sunlight and some growth with a tiny stem for the ones inside (room temperature) with sunlight.
1. During the install, the option to sync with NTP (Network Time Protocol) server was checked. From a security perspective, why is it important for a system to keep accurate time?
In this lab, a lab group will do multiple tests on water for contrasting ions. Tests confirming the absence or presence of the ion. The lab group will be dealing with five distinct solutions. A control sample, tap water sample, ocean water sample, and a distilled water sample. The group will also use a reference solution. A reference solution is a solution with a firm vigorous existence of the ion being tested. So, It is like an example of what the precipitate should look like when the ion is existent and visible in the water sample. The solution may or may not contain an ion. Compare the results with the performance of the reference sample. Finally, if an ion is present, a chemical reaction will happen, making either a precipitate or a solution
Create categories for the “Hemoglobin” variable responses with different cutoffs used medically. The “bed_net_days” variable responses can also be categorized if it is clinically, biologically or epidemiologically applicable for this study.
HCl was added because chloride is insoluble with lead and silver ions.1 Since HCl is soluble in water, applying heat at step 5 caused the bonds to break, which made it dissolve. In step 12 K2CrO4 was added to create a yellow precipitate. K2CrO4 was a good substance to use because it is insoluble with barium.1 The white precipitate of barium could be considered a false positive because the unknown substance could be calcium and the white precipitate would have made it seem as if it was barium. The formula unit equation were K2CrO4 + Pb → PbCrO4 + K and K2C2O4 + Ca →CaC2O4 + K. The total ionic equation were K+ + CrO42- + Pb2+→ PbCrO4 + K+ and K+ + C2O42- + Ca2+→ CaC2O4 + K+.
A flame test is conducted by dipping a wire loop into a solution that contains sodium or potassium ions, and then, once saturated, the loop is heated by a fire. This dissociates the salts into neutral atoms which, when heated to an ever higher temperature, excites the electrons such that they fulfill a higher energy level. When the electrons fall back down to their ground state, the resulting light will be a specific color depending on the ions present. When sodium is present the flame will be an intense yellow color, while the flame will appear violet in color if the solution contained potassium. When both are present together, however, the vibrancy of the sodium overpowers the faint color that the potassium ions emit, such that a filter made of cobalt glass must be used to block out the light of the sodium ions, so that the light produced by the potassium ions may be seen. The first week the experiment was conducted, the flame test was done on the sea water solutions, while the dehydrated salts, obtained by placing a sample of the sea water into an oven and allowed to evaporate, were used during the second
Studies reporting nurse managers views regarding the incidence of adverse work conducts on their units, how it distresses?
CH 204 – Introduction to Chemical Practice Experiment #1– (Qualitative Analysis of Cations) Ashley Gilbert* Claire LeBovidge TA: Ravi Teja February 15, 2017 RESULTS & DISCUSSION The purpose of this experiment was to have found the identity of unknown cations having used qualitative analysis. The unknows were composed of metal nitrate salts and contained either lead or silver and calcium or barium. Also, cation flame test was performed to test and observe the color the flames turned when a wooden stick, dipped in a metal chloride solution, was waved over the flame. If this experiment was to be repeated, a way to improve the current procedure might be to describe exactly what the test tubes should look like in steps that may be confusing, for example in step 11, it
The qualitative data that is collected from my group assessment would be analyzed by reviewing the data collected to gain an understanding of the material then to process the material by examining the data for common patterns of routine. The information that many generalist social workers find out during an intake interview, it very limited information that aid in assisting the client. A lot of the times clients are not forth coming about everything that is happening in their lives.
Purpose: To collect information from past and present Laker employees about their attitude towards work, how comfortable they feel (felt) at work, and their confidence in their boss’s ability to make changes and or difficult decisions. After collecting the data, we will compare the data collected from employees who serve under Jerry Buss to those who have served under Jim Buss. The main objective for this research is to see if a negative tangible difference in the overall work environment had been experience by and or inflicted upon Laker employees due to the changes that Jim Buss has made to the organization’s organizational structure.
The equation is: 2HCl(aq) = Na2S2O3(aq) 2NaCl(aq) + S(s) + SO2 (g) = H2O(l) APPARATUS = = = =
(NH 4 ) 2 Cr 2 O 7 ( s ) Cr 2 O 3 ( s ) + 4H 2 O ( g ) + N 2 ( g )
• Develop a plan for identifying and documenting the logical IP network design and IP addressing schema