Introduction
The objective of this lab was to determine how much precipitate would be formed if BaCl2 was reacted with (NH4)2CO3.
BaCl2 + (NH4)2CO3 —-> BaCO3 + 2(NH4)Cl
0.3mol
Materials
To perform this lab, you will need;
Ring stand
2 pieces of filter paper
4 empty beakers
4.5g of (NH4)2CO3
7g of BaCl2
Funnel, small enough to fit in ring stand.
2 small test tubes
Methods
Begin by pouring the 7g of BaCl2 and the 4.5g of (NH4)2CO3 into two seperate beakers with equal amounts of water. Because both of these compounds are soluble, they should dissolve in the water. Next, mix the two aqueous solutions together in your third beaker. A reaction should take place almost immediately. The reaction taking place is known as double displacement, meaning that the two solutions trade partners. This leaves you with BaCO3 and 2(NH4)Cl. Based on the 4 solubility rules, you can determine that the precipitate formed is BaCO3.
Next, put the folded piece of filter paper into the funnel on the ring stand. Place the 4th beaker under the funnel, and slowly pour in the final solution. The precipitate, BaCO3, will stay on the filter paper, while the 2(NH4)Cl drips through. This is known as the supernatent. Next, test the supernatent for excess 2(NH4)Cl. Because you started with more (NH4)2CO3, the supernatent should contain excess 2(NH4)Cl. To do this, take 2 small samples of the supernatent in small test tubes. Next, pour in the original 2 solutions. As the (NH4)2CO3 is poured in, there should be no change, simply because a solution cannot react with itself. As BaCl2 is poured in, there should be a mild reaction that turns the solution a milky white. This means that there was excess (NH4)2CO3, and that the solution is filtering correctly. Once the first piece of filter paper is full, take it out, and put in the second. After the solution has been completely filtered, the filter paper must be dried. Once the filter paper is completely dry, it can be weighed to determine the mass of the dried precipitate. Be sure to subtract the weight of the filter paper. Because there are 0.03 mol of BaCO3, there should be approximately 5.9g of BaCO3. This is your theoretical yield. Now the actual yield must be determine. To do this, take the weight of the 2 filter papers. Next, the percentage yield must be found. To do this, divide the actual yield by the theoretical and multiply this number by 100. If all was done correctly, then this number should come out to 100% yield.
The Essay on Percent Yield Of A Precipitate
Purpose The purpose of the experiment is to determine the percent yield of the precipitate; by performing double displacement reaction between solutions of two different compounds. Introduction First of all when making a solution of two different compounds; there will many variables that can be considered during the experiment. However, the variables are controlled variables. Controlled Variables ...
Results
Theoretical Yield
O.03mol BaCO3 x 197.33g = 5.9 g BaCO3
1 1
% Yield
% Yield= 5.9g = 1×100= 100% Yield
5.9g
Discussion
This lab was conducted to show how different compounds react with each other, and determine how much of a precipitate will be formed. While there was a 100% yield, there was much room for error. If one of the original solutions had been contaminated with another substance, then the reaction may not have taken place properly. Also, if any of the final solution had been spilled, then you would come with a very inaccurate answer, and ultimately failed the lab. Because a 100% yield was determined, there was little to no error in our experiment. Through this lab, we determined that if 4.5 grams of barium chloride reacts with 7 grams of ammonium carbonate, then your outcome will be 5.9 grams of barium carbonate, and 4.3grams of ammonium chloride.
The Essay on Gram staining lab report
Gram staining is a very important technique used in biology labs all over the world. It is a technique used to differentiate types of bacteria using certain physical and chemical characteristics of their cell walls. Gram positive bacteria (which show up purple after the gram staining process) have a very thick layer of peptidoglycan where gram negative bacteria (which show up pink after the gram ...
