magnessium chloride can be used to distinquish between cabonate and hydrogencarbonate ions. Descrbe how this done with experimental observations
To distinguish between carbonate (CO3^2-) and hydrogen carbonate (HCO3-) ions using magnesium chloride, you can perform a simple experiment called the "lime water test." The procedure involves the following steps:
Materials needed:
1. Limewater (calcium hydroxide solution)
2. Magnesium chloride solution
3. Carbonate and hydrogen carbonate solutions
Procedure:
1. Prepare separate test tubes or small beakers for the carbonate and hydrogen carbonate solutions.
2. Pour a small amount (around 2-3 mL) of the carbonate solution into one test tube and the hydrogen carbonate solution into another.
3. In each test tube, add a few drops of magnesium chloride solution to the respective solutions containing carbonate and hydrogen carbonate ions.
4. Observe and note down any changes in the solutions.
Experimental observations:
1. Carbonate ions (CO3^2-):
- When magnesium chloride is added to the carbonate solution, a white precipitate of magnesium carbonate (MgCO3) will form.
- This precipitate is insoluble in water and can be observed as a white solid settling at the bottom of the test tube or beaker.
2. Hydrogen carbonate ions (HCO3-):
- When magnesium chloride is added to the hydrogen carbonate solution, there will be no immediate visible reaction.
- Hydrogen carbonate ions do not form a precipitate with magnesium chloride.
Therefore, by performing this simple experiment, you can distinguish between the carbonate and hydrogen carbonate ions based on the observations noted. The formation of a white precipitate suggests the presence of carbonate ions, while the absence of a precipitate indicates the presence of hydrogen carbonate ions.