Our theoretical yield of Silver is 0.370 g, and our actual yield is 0.351 g. To begin with, I was amazed of the process of making silver from a little piece of metal and silver nitrate solution even though it took 3 days to complete this lab. On the first day, Michael mostly did all the measurements and testing, while Mai and I was responsible for the calculations, including taking pictures and recording down the data. Firstly, our group balanced out the chemical equation, which is very important for the later steps of our procedure. The equation is 1Cu+2AgNO3Cu(NO3)2 +2Ag ( you can see how to balance it out in the procedure and we are using Copper II for this lab). Moreover, we weighted the copper metal and the scale showed that it was at 0.109g. …show more content…
We got 0.583g as our theoretical yield of silver nitrate, but due to our clumsiness, we scoped out about 0.593 g of silver nitrate. Compared the amount of silver nitrate that we have and the amount that we needed, Silver nitrate ( AgNo3) is our excess reactant and copper is our limiting reactant, which we will using it to find out our theoretical yield of how much silver that we should have make. There is one thing I wanted to mention that we use distilled water instead of tap water because in tap water, it contain other compound such as mineral, or Calcium, etc. Therefore, we do not want any of those to be reacted with our solution and silver, we want to produce pure silver. Next step is we placed the copper metal inside the silver nitrate solution, the color started to change into light aqua blue. After we decanted the solution and dried the silver with the incubator, we weighted the silver and it was at 0.351 g. Compared to our theoretical yield, we should have made 0.370 g of silver, but instead we made 0.351 g of
the solution was recorded. The first test performed was an Anion Elimination Test, the Silver Nitrate
Another source of error was that the size of the filter paper was awfully small. This made it so the chances of spilling the precipitate and not getting it in the funnel was much greater than it should have been. Some of the product was lost during the transfer from the beaker to the funnel due to this factor, in the end reducing the total yield recovered. Lastly the substances used may not be 100% pure, this means that the mass of the reactants could have been less than the actual measured amount. This means the mathematically calculated theoretical yield was larger than it should have been.
Nitric acid reacts. Removes the ions that might also give a unclear precipitate with silver nitrate. White precipitate is formed. Bromide Equation: Ag+ (aq) + Br- AgBr (s)
(c) One can determine that they have added sufficient Mg in Reaction V by adding additional amounts until the gas bubbles stop forming. (d) A litmus test will be performed to determine whether or not the Mg in the reaction has completely reacted because the paper’s blue color will disappear once the reaction is over. The student’s mass percent recovery of Cu is 91.89% which is found by dividing 0.34g by 0.37g and multiplying the answer by 100%. Results: Chemical Reactions: Chemical equation: Cu(s) + 4HNO3(aq) → Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l)
The first source of error may have been after the reaction when we were rinsing off the copper from the iron nails. We may have not removed all the copper from the nails before measuring the new mass of the nails. The second possible source of error was when we were decanting the liquid from the first beaker into the second beaker. Some of the copper solid was in such small pieces, it was too difficult save every piece from falling into the second beaker. When measuring to find the amount of copper produced, not all of it was there since some slipped by into the waste beaker.
The most prominent error for this lab is the actual mass of the product. The actual mass of the copper we obtained is greater than the theoretical yield. The actual mass of the copper is 2.436 grams and the theoretical mass is 2.343 grams. The percent yield exceeds 100% and there is a great percent error of 3.969%. The cause of this error could possibly be the result of the impurity of the product. The solid copper product was left in the oven to dry overnight. It is possible that not all of the water has evaporated from the solid copper which would greatly influence the mass of the product. Another possibility is the accumulation of particles from the atmosphere into the solid copper and onto the filter paper. While the product was wet, dust particles from the air could have been pulled into the moisture.
D. You suspect dissolved silver ions in a solution. How would you test this solution to confirm the presence of the silver ions?
The pigment that we chose to create is a combination of the reactants copper nitrate and sodium phosphate. This combination will create a bright blue color. The balanced equation for this combination is 3 Cu(NO3)2 + 2 Na(PO4) = Cu3(PO4)2 + 6 Na(NO3).
Results: Mass of copper wire: 0.28g Mass of empty beaker: 68.49g Mass of beaker and dry copper: 68.84g Mass of recovered copper: 0.35g Percent copper recovered: 0.35g / 0.28g * 100% = 125% Observations: When the 2.0 mL of concentrated nitric acid is poured onto the copper wire, the solutions turns green at first, with a lot of rust-coloured gas coming out the top. The solution slowly turns blue as the copper dissolves, and less gas is emitted. When the reaction is complete, Cu(NO₃)₂ is left in the solution. When Cu(OH)₂ is added to the solution, the solution turns a darker blue and appears to have particles in it.
The information above shows the results observed from the experiment. The unknown substance was first observed to be a white, powder that had no smell. When it was mixed with the water, it produced a clear odorless solution. The pH was taken immediately from the solution once it was mixed properly. The pH came out to a 10 on a 14 level scale. This indicated that the solution was a strong alkaline base. With this information, the list of possible solutions are narrowed down to only basic solutions. After dividing the solution into five test tubes, the first test was conducted. The first test was conducted using silver nitrate. The results shows a milky white precipitate. According to Doc Brown, an online informational website, by adding the
We came to this conclusion with the understanding of our solubility curve. As a solution increases in temperature, the concentration of Copper Sulfate becomes more soluble and dissolves into the water. When taking away the heat source, the solution begins to cool becoming a supersaturated solution. The excess of dissolved solids creates an unstable solution, therefore, to regain a stable form, the solution will begin to form crystals growing from the seed crystal. Our solubility curve shows that with our .625 g/ml concentration, crystal growth will begin at 70°
Then 1-2 drops of the solutions of interest are placed in the test tubes. The following reactions are expected for the silver nitrate
On the first day, if the substances have a significant amount of precipitate, then the substance will require a greater number of drops of sodium hydroxide than substances with an insignificant amount of substrate. On the second day, if the starting reactants affect the yield of the product then obtaining solid copper from a salt will result in a greater yield. If aluminum foil is the limiting reactant of the experiment, then the percent yield will increase as the amount of foil increases.
In this lab we are going to create silver ornament using oxidation which is a reduction chemical reaction. The process used in this lab is similar to how silver mirrors are created. Mirrors have been around for many years, dating back to at least 3,000 years ago in China and the Middle East. The method for making these mirrors consisted of the hammering of bronze, copper, or tin sheets to make them smooth. The making of glass was developed in Rome in ancient times and 17th century Italy craftsmen had made a better method of lining the glass with the reflective metals that were listed before. Another process, created by a German chemist by the name of Justus von Liebig, involved the silvering of glass sheets with a thin layer of silver
The results suggest that the Theoretical Yield was 4.2246 grams and the Actual Yield was 4.24 grams, which gave a Percent Yield of 100.473% and a Percent Error of 0.473%. The actual yield was greater than the theoretical yield. It is suggested that it was greater than because I used two different filter papers and I only measured one. If I had measured the two different papers, I would probably obtain a different mass for each of them. Because I am only off by 0.02 grams, that could have been the reason why I didn’t get the mass I should have obtained.