pre-lab Questions
1. What is one difference between qualitative and quantitative analysis?
2. Use Table 1 to determine which metal ion would be identified as the reactant if a reaction with ammonia produces a violet complex? Use scientific reasoning to explain your answer.
3. Use the pH scale to describe an acidic solution and a basic solution. At what pH would a solution be considered neutral? Why?
experiment 1: qualitative analysis of reactions
Data Sheet
Table 2: Litmus Test Results of OH- and H+ Solution Type Initial Litmus Color Final Litmus Color Acid or Base? Acetic acid Purple Red Acid Sodium bicarbonate Purple Blue Base Table 3: Test Results Solution Type Indicator Observations Initial Final Carbonate Ion Bubble formation when an acid is added Clear solution Bubbles Sulfate Ion White precipitates when barium chloride is added to the solution. Clear solution White precipitates Phosphate Ion Formation of white precipitate Clear solution White precipitate formed Calcium Ion Formation of precipitate Clear solution Precipitate Table 4: Determination of an Unknown Results Carbonate Ion Test Tube Sulfate Ion Test Tube Phosphate Ion Test Tube Observations No bubbles observed. Solution remained clear No precipitate White precipitate formed Result: Positive or Negative? Negative Negative positive
Post-Lab Questions
1. What ion is contained in the unknown solution? Use your results as evidence.
2. Imagine that the unknown solution contains aqueous ammonium sulfate, which is commonly used in fertilizer. Write a balanced equation for the precipitation of barium sulfate after mixing aqueous ammonium sulfate and barium chloride.
3. Identify and discuss any sources of error for this experiment. How could you mitigate error?