Question

During a flood, the labels from three bottles of chemicals were lost. The three unlabeled bottles of white solids were known to contain the following: strontium nitrate, ammonium carbonate, and potassium sulfate. Explain how you could easily test the substances and relabel the three bottles.

Answer 1

To identify the lost labels of strontium nitrate, ammonium carbonate, and potassium sulfate, we can add HCl to observe the release of CO2, conduct a flame test for distinctive colors, and perform a solubility test.

Step-by-step explanation:

To relabel the three bottles of chemicals that are unlabeled after a flood, we would need to conduct tests that distinguish strontium nitrate, ammonium carbonate, and potassium sulfate from one another. Here are some steps to identify each one:

1. 1. Add a few drops of hydrochloric acid (HCl) to a small sample of each chemical. Ammonium carbonate will react with HCl to produce carbon dioxide gas, which you can identify by bubbling or fizzing. The chemical reaction is NH42CO3 + 2HCl → 2NH4Cl + CO2 + H2O.
   2. Conduct a flame test. Dab a small amount of each salt onto a wire loop and place it into a flame. Strontium compounds tend to color flames crimson red, which is distinctive from potassium, which colors the flame lilac. Since potassium sulfate doesn't undergo a distinguishing reaction with HCl like ammonium carbonate and does not yield strontium's red flame, the sample that gives a lilac flame without fizzing is likely potassium sulfate.
   3. Test the remaining chemicals with a solubility test. Strontium nitrate is soluble in water, so if the remaining sample dissolves easily, it is strontium nitrate. Since we've already identified the other two compounds at this point, the process of elimination can be used.