Unknown Alkali Carbonate

Identification of Unknown Alkali Carbonate

Introduction:

For this project, our team has been tasked to identify an unknown alkali carbonate using 6M HCl as a reactant. Since the products of this reaction will invariably be a alkali-chloride precipitate, as well as H2O(l) and CO2(g), we should be able to eliminate superfluous calculation by simply evaporating the remaining aqueous solution that is combined witht the remaining H2O(l). The remaining solid should be the metal-chloride precipitate. If we can determine the molar mass of each alkali metal we should be able to use stoichiometric principles to calculate the weight of each alkali-chloride precipitate and compare it against the weight of our experimental precipitate. Thus, the result that most closely matches the calculated weight should be the identification of the unknown alkali carbonate.

How we performed the experiment:

For our experiment, we added hydrochloric acid to a solution of deionized water and an unknown alkali carbonate “D”. We added 0.6M HCl(aq) until we could verify that the solution had reacted completely by watching for the bubbling to stop. To make sure the acid and the unknown substance fully reacted, we used a glass stirring rod to stir the solution. We also used a 125mL Erlenmeyer flask to make sure none of the solution would splash out. In case that any solution did splash out we had clear plastic screen underneath the flask to catch the splashing of the solution. We then used deionized water to rinse the solution off of the screen and glass rod and back into the flask. Next, we moved to the fume hood and set up a ring stand with a clamp. We then put the wire gauze above the clamp then put a 125 ml of water in 250 ml beaker on top of the wire gauze. To ensure we made more efficient use of our time, we added two boiling chips in the beaker. Then, we poured the solution from the flask into the evaporating dish, making sure that when we placed the dish on top of the...