Katherine Sun CTD Chem Blog

Introduction: Using solubility curves of known solids can help identify an unknown solid. In this lab we used the solubility curves of 3 salts to determine if the unknown salt we were given is sodium nitrate, potassium nitrate, or sodium chloride. The primary purpose of doing this lab is to understand how to utilize solubility curves and how to transfer the results of the experiment to the graph in order to achieve the final goal of identifying the unknown salt. Procedure: After receiving the unknown solid, we heated the 10mL of water to 50 degrees Celsius and added 5.0 grams of the unknown solute to determine if the solute was sodium chloride. After doing so, we then attained 10 mL of ice water, at 10 degrees Celsius, and added 5.0 grams of the unknown solute to determine if it was potassium nitrate or sodium nitrate. When deciding on what temperature to heat the water, we chose temperatures where the solubility of the three salts varied greatly. Data/Discussion: We added 5.0 gram...

Introduction: Alka Seltzer tablets contain sodium bicarbonate and citric acid, which when dropped in water, dissolve and react to produce carbon dioxide gas. In this lab we dropped 2 Alka Seltzer tablets into a test tube filled with water and then wrapped a balloon around its rim. When the Alka Seltzer stopped fizzing, we measured the circumference that the balloon blew up to. Furthermore, using the ideal gas law, we determined the mass of the carbon dioxide gas produced. after Alka Seltzer was dropped into the test tube Data Table:  Calculations:  Analysis Questions Discuss an area in this lab where experimental error may have occurred.  When we were transferring the ground Alka Seltzer tablets from the plastic tray to the balloon, we inevitably lost some of it and could not remeasure how many grams of the alka seltzer tablet remained. Another source of experimental error was our inability to measure the circumference of the balloon per...