Soda Ash Experiment Essay Example for Free

Soda Ash Experiment Essay To determine the efficiency of a titrimetric and potentiometric method while determining the carbonate in soda ash, both a t-test and f-test were performed. The t-test proved accuracy between methods and the f-test proved no difference in precision. Introduction Soda ash is a white anhydrous material that be found in either powder or granular form and it contains 99% sodium carbonate when shipped[i] (1). Soda ash serves a purpose in the manufacturing of many economically important products such as the manufacturing of glass, chemicals, paper, detergents and other products. Soda ash has been used dating all the way back to 3500 BC by the Egyptians. The Egyptians were able to utilize soda ash then in the production of glass and then as an ingredient in medicines and breads by the Romans (1). Today, the majority of the world’s soda ash comes from trona ore, which is mostly found in the Green River Basin, formerly known as the Gosiute Lake, located in southwest Wyoming. The Green River basin is actually a prehistoric alkaline lakebed that supplies this vast amount of trona ore (1). With glass manufacturing being the largest application of soda ash, it erves very high importance in the production of containers, fiberglass insulation or flat glass for housing commercial building and automotive industries[ii] (2). Not only is the use of soda ash in glass manufacturing important, but it is also used to clean the air and soften water (2). With all of the new arising concerns with the environment with emissions in the atmosphere, the demand for soda ash h as increased. This is so because soda ash can be used to remove sulfur dioxides and hydrochloric acid from stack gases present in the atmosphere (2). Since sodium carbonate has a strong base, it is commonly used to neutralize acidic effects so when a photographer were to develop film, he would use soda ash to stabilize the alkaline condition or a person who owns a pool would use it as an additive to chemically neutralize the water since chlorine makes the pool acidic (1). Soda ash has a high pH in concentrated solutions and can irritate the eyes, respiratory tract and skin. It should under no circumstance be ingested because soda ash can corrode the stomach lining (1). In the experiment that was conducted Na? CO? eacted with 0. 09356 M hydrochloric acid. Methods In the first part of this lab, roughly 1. 855g of sodium carbonate was weighed and put in the oven to dry at a temperature of 110 degrees Celsius for 2 hours. In part B, a 1 L solution of 0. 1 M HCl from 12. 0 M concentrated HCl was made to serve as the titrant for the lab. Do not discard the solution because it is used for both parts of the lab. Perform a rough titration of the dried standard Na? CO? with 0. 1M HCl to standardize the solution. The size of the sample weighed out should be enough to neutralize about 25 mL of 0. M HCl. On an analytically weighed balance weigh one sample of the dried primary standard sodium carbonate into a 125mL Erlenmeyer flask. Dilute the sample with 25mL of de-ionized water and then add roughly 4-5 drop of indicator Methyl Orange and titrate the solution to a point prior to the endpoint. Gently heat the sample solution on a hotplate in the fume hood until condensation appears around the neck of the flask to expel dissolved CO? from the sample. Cool the solution in an ice bath and finish titrating the roughly 0. 1 M HCl into the sample. A small amount of titrant is needed to reach the endpoint. Based off of the R value obtained from the rough titration, accurately weigh three more samples and repeat the titration. This data will be used to calculate the exact concentration of the HCl solution. In part C, titrating the unknown, accurately weigh about 0. 2g of dried unknown into a 125 mL Erlenmeyer flask and then add 25mL of de-ionized water and 4-5 drops of indicator (same as used in the rough). With the same procedure used in the standardization, titrate to just before the endpoint. Based off the R value from the rough titration of the unknown, accurately weigh 3 more samples and repeat the titration. In the second part of this lab, use a pH meter to titrate the unknown sodium carbonate. The instructor will help in setting up and calibrating a Vernier pH meter. The pH meter is calibrated with two buffer solutions with a pH of 4. 01 and the other with a pH of 10. 00. Based off of the calculated R value from part C accurately weigh two samples of the dried unknown sodium carbonate into two 150mL beakers. Add 25mL of de-ionized water to the first sample and place the electrode in the solution as well as a teflon stir bar and glass stirring rod and place on a stir plate. Record the initial volume of the HCl in the buret and carefully titrate with HCl until the pH is between 6. 0 and 6. 5. Be careful because the pH meter tends to lag. Once the target pH is achieved stop adding HCl and record the volume of the buret. Remove the sample beaker from the stir plate and put the electrode in a beaker filled with warm water. Warm the solution for a few minutes on a separate hot plate to expel dissolved CO?. Cool in an ice bath and return to the stir plate. Record pH, first data point, and continue to add increments of HCl until a pH of 2. 5 is achieved. Be sure not to add any de-ionized water after the first pH point is recorded. When completed there should be 30-40 data points. Repeat for the second sample. Results Table 1: Mass of the unknown Na? CO? to determine carbonate in soda ash based off titrimetric method (Part C) Titration |Starting mass of weigh bottle and unknown Na? CO? | |46. 848% Na? CO? |51. 933% Na? CO? | |46. 5879% Na? CO? |50. 564% Na? CO? | |46. 7083% Na? CO? | | |47. 0692% Na? CO? | | |46. 6548% Na? CO? | | |46. 7396% Na? CO? | |