Determination of Na2CO3 in Soda Ash Rachel Swanson February 14, 2018 CH355L-2E Introduction Titrimetric analysis was used in forcing the reaction shown below to reach acid-base neutralization. Neutralization is reached by adding a known volume and concentration of one reagent to a sample in solution.1 The equivalence point takes place once all available ions have been reacted.2 The endpoint, a change in color, occurs when excess solution is added to react with the sample solution after all ions have already been reacted. An abrupt change in color, in this experiment orange-pink, occurs when all ions have been used up.3 This method was used in standardizing HCl solution in order to use the calculated concentration to …show more content…
Titrating three trials with a known molarity allowed the mass of Na2CO3 to be determined experimentally. The measurements for each trial was shown in Table 1. Soda ash was experimented without interference of its impurities by utilizing the titration method.1 Knowing the molarity of the HCl solution while titrating soda ash allowed the moles of Na2CO3 found in soda ash to be calculated by the recordings of the titrant volume used and the mole ratio relationship shown in (1). The mole ratio can be used and converted into solving for the mass of Na2CO3 in order to solve for the weight percentage found in the unknown sample. Three trials of titration were tested and recorded. The three trials resulted in three calculations for the weight percent of Na2CO3 in the unknown experimental sample. The average percentage of the three trials was determined and reported with error in Table 2. Overall, the relationship in the reaction shown in (1) allows the calculation for mass to be transferred from different substances. The known molarity of standardized HCl solution is an important first step in the continuation of this experiment in order to calculate Na2CO3 in soda ash. The weight of of the unknown sample and the titrant volume with the known molarity were the key values in determining the weight percentage of the compound in soda ash. The weighed sample of the unknown was the mass solution used in …show more content…
The standardized HCl solution, the measurements from titrating, and measurements of the unknown sample allowed the mass of Na2CO3 to be determined. This mass was then used in (2) with the mass of the unknown sample in order to calculate the weight percentage of Na2CO3 in soda ash. The average weight percent of the three trials experimented was 36.93±0.08 wt%. Sources of error resulted from the standardization of HCl solution. Two trials were completed instead of three which caused a lower calculated molarity of the standardized solution that was used in calculating the mass of Na2CO3 in soda ash. Since there were only two completed trials, Grubb’s Test could not be completed in determining outlier’s in the data set. These outlier’s can result in offset numbers in the overall calculation for weight percent. The experiment for determining Na2CO3 in soda ash could be improved by completing more titration trials in order to depict more accurate results for both the standardization of HCl solution and calculating for the weight percentage of Na2CO3. More trials can rule out outlier’s by using Grubb’s Test which will leave the sample data set with better results in the
Discussion The purpose of this lab was to measure the mass of a solid reactant, in this case, NaHCO3, which is also known as baking soda, and to find the mass of the solid product NaCl (salt) as well. From there, the masses were to be converted into moles and created into ratios that showed the relationship between the reactants and products. That information was then compared to the theoretical data in order to check its accuracy and reveal the significance of mole ratios in chemical reactions.. During the experiment, hydrochloric acid (HCl) was added to the baking soda in order to begin the reaction.
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.
From the results that were acquired from mixing the liquid reagents with each powder, it was determined that Unknown Mixture #1 consisted of baking soda and cornstarch. When individually testing the substances from Unknown Mixture #1 with the liquid reagents, a few noticeable reactions occurred. Mixing baking soda with vinegar caused bubbling to occur. This is because a neutralization reaction took place between the two reactants. In this reaction, sodium bicarbonate(baking soda) reacts with vinegar and produces sodium acetate, water, and carbon dioxide(HC2H3O2(aq) + NaHCO3(aq) NaC2H3O2(aq) + H2O(l) + CO2(g) ). The gaseous carbon dioxide most likely tried to escape into the atmosphere and caused the bubbling to occur. Another noticeable reaction
The procedure to obtain the mass lost for these two reactions was to first calculate the mass of HCl. For the first reaction, which was sodium bicarbonate, the mass of the beaker was weighted, then the grams of NaHCO_3 were added to the beaker and the mass was weighted. After recording the mass of the beaker with the NaHCO_3, 25 mL of HCl were added to the beaker and the mass after the reaction was weighted. To determine the mass lost in the reaction, the initial mass of the reagents was subtracted with the final mass of the reagents. The same procedure was performed with the sodium carbonate reaction, however 50 mL of HCl were used instead of 25 mL. Each chemical reaction was
Since the neutralization reaction yields H2CO3, it's decomposition would produce carbon dioxide gas, which would bubble out of the solution. The neutralized solution was placed back into the funnel and the aqueous layer drained; after this washes with 10 mL of concentrated brine and 10 mL distilled water were performed to remove the NaCl and water produced during the neutralization out of the organic layer containing 2-chloro-2-methylbutane. The latter was then dried with anhydrous sodium sulfate, after which the percent yield of the liquid product was
All of our observations and calculations reflected in our results. Our theoretical yield was 101.68g and our actual yield was 94.22g. This would make our percent yield 92.66%. Our procedure was to observe and measure the mass of the Aluminum strip was obtained, then measure out 50 mL of HCl and record the mass, next put the strips of aluminum into the weigh boat and record the mass of the aluminum and the acid together, then you place the aluminum into the acid and make observations, when the aluminum is completely dissolved, record the mass of the solution. We believe that our results are not very good because they are not accurate due to the fact that we let the solution sit for two days causing some of it to evaporate. Next time we would measure the final mass right after the aluminum completely dissolves. This lab relates to what we learned in class because it proves that stoichiometry is realistic and can be used to make the correct ratios for chemical
The experiment was a success because all of the ultimate goals were completed. The volume of CO2 released from the pop rock reaction was calculated and found at 58 mL. The moles of CO2 was calculated at .00233 mol. The experiment was also a success because it was found that the heat released from combining and eating pop rocks with soda would not kill the consumer unless it was consumed in very high doses. The combination is not dangerous because it doesn't release a large amount of heat. The simulation of stomach acid, pop rocks, and soda reviled that the temperature increase during the reaction is minimal. Some possible errors of this experiment was missing some of the CO2 when the tube escapes the graduated cylinder. To avoid this in the future the tube could be held during the apparatus processes. Another possible error is miscalculation of LD50. In the future calculations could be done more precisely and
mL) x (1 mol Na2CO3 / 1 mol CaCO3) x (1000. mL Na2CO3 / .50 mol Na2CO3) = 4.0 mL, 4.0 mL (1.2) = 4.8 mL (0.200 g x 1 g / 1000. mg) / (.0200 L) x (1/100) = 40.1 mg/L Experimental Water Hardness (with classification) and Percent Yield
What is the Concentration of Acetic Acid in Each Sample of Vinegar? Throughout this Acid-base titration and neutralization reaction lab, the goal was to determine the concentration of acetic acid within three given samples of vinegar. This titration is based on the argument that acids and bases neutralize each other when they are mixed together using an exact stoichiometric ratio. During this investigation we determined the concentration by performing an acid-base titration with the use of an universoul indicator.
The materials that were used were 1 100 mL graduated cylinder, 1 Bunsen burner, 1 flint lighter, 1 weight boat, 1 rubber stopper with one hole opening, 3 30 mL test tubes, 1 30 cm rubber tubing, 1 tub, 2 retort stand, 2 utility clamp, 1 scoopula, 1 electronic balance, 1 test tube rack, 9 g of baking soda, 1 test tube brush and finally a timer. Prior to the start of the experiment, it was ensured that all materials were clean, functional and not contaminated or cracked for one’s safety and efficiency of the experiment. Furthermore, the procedure that was taken, with regards to getting the best results was 1. Wore safety glasses to avoid any splashes of chemicals, observed and recorded qualitative data of baking soda.
Results and Discussions After filtration, 5.256 g of sodium bicarbonate was obtained. An experimental error in this experiment was that 100 percent of the carbon dioxide did not go through the nalgene tube because some went up the thistle tube. Another source of experimental error was that not all of the sodium bicarbonate could be rinsed off of the glassware and not all of it was filtered. Both sources of experimental error led to a lower yield. Precipitation reactions could have been done to confirm the presence of carbonate ions in the product.
The standard deviation and relative standard deviation show that there were errors in the experiment to create some imprecision. The errors were from slight errors in measuring during lab and some error with using the pH electrode. There were also some errors made when carrying the titration, which caused problems in the data. The data shows that only about 36% of soda ash is actually sodium bicarbonate; this means that the majority of soda ash is composed of other chemicals. With the errors in the procedure this could have caused inaccuracy in the results that cannot be found because it is an unknown sample.
The solvent used was Hydrochloric Acid. In determining the solubility the acid was used to breakdown the structure of the calcium hydroxide, which determines the solubility product constant. The results of the experiment show the final concentration of Ca(OH)₂ to be averaged around 18.98mL. However many mistakes could have occurred that would give an inaccurate final
A mock trial was performed to approximate the 1st and 2nd equivalence point regions. The HCl titrant was added into the soda ash solution in increments of 1.0 mL until the pH was close to ~3.0-2.0 then, the HCl solution was dispensed in increment of 0.1 mL until the pH was exactly 2.0. The volume of the titrant added and the pH was recorded. With the aid of the instructor the 1st and 2nd equivalence was determined based on the pH/mL change. This method was repeated once more; as instructed although the experimental procedure stated to do perform four trials. The calculated amount of soda ash was weighted and the mass was recorded. The soda ash was then transferred into a 250 mL beaker and dissolved in 70 mL of water. 1.0 mL increments of HCl solution was dispensed until 2 mL before equivalence point 1 then HCl was added in 0.3
Stoichiometry has many uses in the real world. In the chemical industry and in professional scientific experiments, scientists use stoichiometry to save money. Scientists use stoichiometric calculations to determine the amount of a substance they need to purchase for a specific reaction. There are four possible reactions that can occur when sodium bicarbonate thermally decomposes. In this lab, stoichiometry was used to find out which balanced chemical equation out the four best represents the thermal decomposition of sodium bicarbonate.