Second Cation Lab Report

After identifying the first cation, the following procedures identified the second cation, which was barium or calcium. The second cation was identified by using the liquid portion of the solution mixed with hydrochloric acid and separated from the white precipitate, silver chloride after being centrifuged. Ammonium carbonated, which serves as to help confirm the presence of either barium or calcium cation, was added and stirred to this existing solution, causing the solution to become cloudy and white. Afterwards, the solution was heated and occasionally stirred in a hot water bath, the white precipitate began settling at the bottom of the test tube, which could be either barium carbonate or calcium carbonate. Once the test tube was left to cooldown, it was

Acetic acid was then added to the test tube and stirred until fully dissolved, water was then added and stirred until the solution became clear. It is crucial that the acetic acid completely dissolves into the solid because it causes the barium carbonate or calcium carbonate to dissociate, which results in barium or calcium ions in the water, preparing the ion for the addition of ammonium hydroxide and potassium chromate. If the acetic acid fails to fully dissolve in the solid, it will prevent the barium or calcium from reacting with the chromate ion in the following step thus deeming the results in a false positive. In other words, the solution would appear as if barium or calcium was not present in the solution, although in reality it is present. Following the full integration of acetic acid, ammonium hydroxide and potassium chromate was stirred in to the solution, causing the solution to become orange; however, a precipitate did not form. Potassium chromate was mixed with the solution to identify if barium or calcium was present because potassium chromates dissociates into potassium and