Lab Report On Carbonate

1. To titrate a hydrochloric acid solution of “unknown” concentration with standardized 0.5M sodium hydroxide.

The pre-test helped us decide the exact details of our experiment. We started off with testing 25cm³ of 3-molar hydrochloric acid to 2g of calcium carbonate medium size chips (we decided a medium size chips before we started our pre-test as we had a choice of 3, small, medium, large). We saw that this reacted too quickly as we used 10 second intervals and we couldn't get 6 results this is because our burette could only hold 100cm³ of water, which would make our results reliable. We then decreased the amount of Calcium Carbonate to 1g and kept the same 25cm³ of 3 molar hydrochloric acid and 10 second intervals. We could get the right amount of results of this, so we then tested the other extreme - the lowest molarity.

The mole is a convenient unit for analyzing chemical reactions. Avogadro’s number is equal to the mole. The mass of a mole of any compound or element is the mass in grams that corresponds to the molecular formula, also known as the atomic mass. In this experiment, you will observe the reaction of iron nails with a solution of copper (II) chloride and determine the number of moles involved in the reaction. You will determine the number of moles of copper produced in the reaction of iron and copper (II) chloride, determine the number of moles of iron used up in the reaction of iron and copper (II) chloride, determine the ratio of moles of iron to moles of copper, and determine the number of atoms and formula units involved in

The goal of this lab was to determine the amount of grams of sodium bicarbonate (NaHCO3) required to produce enough CO2 gas to completely fill the lab and also how many Alka-Seltzer tablets that would equate to. This was done by collecting CO2 gas by inverting a buret and submerging it under water in order to calculate the volume of CO2 released from a fragment of Alka-Seltzer tablet. The main component of Alka-Seltzer is sodium bicarbonate, used to neutralize excess stomach acid during illness through the following reaction that generates CO2:

In this experiment, the precision of percent by mass of sodium carbonate was decent. It seemed to be consistent, although we seemed to have an outlier in our fifth trial. I believe this was due to human error of adding too much vinegar to this graduated cylinder. The accuracy of our results was decent in comparison to the rest of the class’s data, but our results were on the higher end compared to the averages of the class data, though not too high to be considered

The purpose of this experiment was to mix Alka-Seltzer with Hydrochloric acid in order to analyze Sodium Bicarbonate as an active ingredient in the Alka-Seltzer. The mixture will contain hydrochloric acid to only see the composition of Sodium Bicarbonate in the tablet once it reacts. The amount that reacted allowed us to determine how much of it is present in the tablet. The amount of sodium bicarbonate will be measure by using the ideal gas law PV=nRT. The experiment will be conducted in the lab, therefore we are going to use room temperature which ranges from 15 to 26 degrees celsius. At room temperature pressure ranges from 12.8 to 25.0 millimeters mercury according to its corresponding room temperature.In the ideal gas equation R is 0.08206latm/mol k which is a constant. Once we have those values we can calculates the number of moles that reacted in the mixture by solving for the missing value. With the number of moles we are able to find the mass in grams which is what will potentially tell us the composition of Sodium Bicarbonate in a tablet of Alka-Seltzer.

In the first part, the production of CO2 gas from sodium bicarbonate and HCl supported the concept that carbonates produce CO2 when reacted with acids. Additionally, the idea of acidity and basicity were confirmed when sodium bicarbonate, which consists of the conjugate acid of a strong base and the conjugate base of a weak acid, yielded a basic pH upon the addition of water. Part two and chromatography utilized the idea of intermolecular forces and attractions to separate out the various substances. Aspirin was the most attracted to the eluent, as it moved up the quickest, while the unknown and caffeine were much slower and stayed near the bottom of the

Throughout the course of the experiment, the weight of the beaker and liquid, the weight of the Alka-Seltzer tablet, the weight of the beaker with liquid plus the weight of the tablet, and the weight of the beaker with all of the contents after the bubbling ceased remained roughly constant and did not vary widely. However, a trend is able to be seen in Figure 1. It is clear that as the mL of vinegar used in each experiment run increased, the mass percent of NaHCO3 increased as well. During the construction of Figure 1, experiment runs four and six were deleted to create the expected graph which consists of a gradual increase and eventually leveling off into a plateau.

Next, add concentrated HCl drop wise until the litmus paper indicates that it is acidic. During this procedure, I added to much HCl because many CO2 gas bubbles evolved. This error in the experiment will cause the recovery % to be lower.

The volume of carbon dioxide gas produced from a reaction was measured in order to determine what carbonate sample was used. A gas assembly apparatus was used to capture the gas from a reaction between an unknown carbonate and 6M hydrochloric acid; three trials were performed. The mass of the unknown carbonate was determined, and the reaction occurred in a test tube. The volume of gas produced by the reaction was measured, and the partial pressure of carbon dioxide was calculated after the partial pressure of water vapor was determined using Dalton’s Law of Partial Pressures. The percent mass of carbon dioxide gas was then calculated, and the average mass percent was compared to the table of known carbonates. It was concluded that the unknown carbonate sample used in the reaction was magnesium carbonate.

The amount of soda ash needed for the experiment was calculated using the following equation: sample weight of unknown=0.1103M (18ml×150.99)/(10×2× %〖Na〗_2 〖CO〗_3 ) An analytical balance was used to weight the calculated amount of soda ash. A piece of weighing paper instead of a weighing boat was used. The mass was recorded. The weighed soda ash was transferred into a 250 mL beaker, then the sample was dissolved in approximately 70 mL of water. The pH meter and electrode was obtained, rinsed with DI water, and calibrated using pH 7 and pH 4 buffer. A burette was obtained, mounted on a ring stand, and filled with the standardized HCl solution, that was prepared in Experiment 2. Since magnetic stirring bars and stirring plates were not available, the students

The retained solution from the NaHCO3 extraction was used to precipitate the P-toulic acid. Drop wise 3M HCl was added to the extracted solution carefully until no more precipitate was formed and the solution tested acidic, with a pH reading less than 3 as indicated by pH paper testing. A piece of clean filter paper was then weighed and the mass recorded in a lab notebook. A vacuum filtration system was constructed with a Buchner funnel

Before the lab began, stoichiometry was used to predict the net weight of the solids for each reaction. For each trial, the crucible was weighed to calculate the true weight of the NaHCO3 sample before and after it decomposes. A 2g sample of NaHCO3 was weighed out in the crucible. Using a Bunsen burner, the sample of NaHCO3 was heated past 200°C for 4 minutes to allow a thermal decomposition reaction to occur. The sample was taken out of the heat and its weight was recorded to measure the weight of the new solid. The sample was put back into the heat for an additional 4 minutes and weighed again until there was no significant change in the weight to ensure that the reaction had taken place. After washing out the crucible to remove the possibility of a different reaction with the solid and to obtain

6. The precipitate may have not dried up properly making it so there was water adding weight on it.

A standard acid solution like HCl can be used as titrant for the analysis of both soda ash and a carbonate-bicarbonate mixture. In the analysis of soda ash, the volume needed to neutralize the soda ash is used to compute for its alkalinity, in this experiment we obtained a 17.6 % alkalinity with an error of 15.14% In the analysis of a carbonate-bicarbonate mixture two indicators (phenolphthalein and methyl orange) were used. The first endpoint determines the half-neutralization of the carbonate and the second determines that of the