Gravimetric Analysis Unknown Metal Carbonate

In this experiment, gravimetric analysis will be used to determine the unknown metal carbonate. Gravimetric analysis. Gravimetric analysis is a method where an ion being analyzed can be classified through their mass (Yoder 2018). Due to the fact that carbonates can be hygroscopic, which means it would be able to absorb water from water vapor, extra precautions have to be taken place to be able to get an accurate mass (Helmenstine 2017). This can be done by using a drying oven and a desiccator. A desiccator is a container that holds drying agents that keep away moisture and water from objects. By heating up the unknown and then putting it in a desiccator, it gets rid of water and moisture. The possible unknown metal carbonates in the experiment
Then it was heated for 3 minutes in the drying oven, and transported into the desiccator where it cooled. Next, the beakers, scoopula, stirring rods, graduated cylinder, and funnel were all cleaned and dried. Then the 50 mL was labeled “M2CO3”. Next the mass of the crucible was recorded and put into a data table. 2 grams of the unknown metal carbonate was put in the crucible and was heated over a bunsen burner for 5 minutes using gentle heat, and then was cooled in the desiccator. Once cooled, the mass of the crucible with the unknown carbonate was recorded and put in a data table. The crucible content was then added into a 400 mL beaker and 200 mL of deionized water was also added in to the same beaker. The contents were mixed together until the unknown carbonate was fully dissolved. 125 mL of calcium chloride was then put into a 250 mL beaker and then was added into the 400 mL beaker with the unknown carbonate and water. The precipitate was settled for five minutes. Next the mass of a dry filter paper was recorded and put in a data table. To set the filter, an iron ring was attached to a ring stand and then a funnel was placed in the iron ring. The filter paper was then folded and put into the funnel. Then a 200 mL beaker was placed underneath the funnel. The 400 mL beaker was then poured into the funnel. The liquid should not be high enough to overfill the filter. Once 10 mL of the liquid was left, the
The unknown carbonate was classified as K2CO3. This was supported by the data collected. For example, the measured mass of 1.3 for the precipitated CaCO3 found in Data Table 1: Mass of Important Objects was used to determined the molar mass of M2CO3, which was 146.15 g/mol. Based off the possible unknowns, K2CO3 had the closest molar mass which was 138.21. This supports the claim that the unknown was K2CO3.

The percent error of this experiment was 8.33%. While the range of an acceptable error rate can change based off the application, a good percentage error would be 5% or below. Therefore, the percent error of 8.133% was a little high. This could have occured because of using a piece of paper instead of a proper filter the possible loss of mass when transporting the unknown into the crucible, solution, filter paper, or the