You have a solution that contains Ca2+ ions and another that contains Na+ ions. How would adding a solution that contains CO2-3 ions enable you to tell which is which?

Adding a solution that contains CO2-3 ions (carbonate ions) would enable you to differentiate between Ca2+ ions and Na+ ions. The carbonate ions can react with Ca2+ ions to form a precipitate of calcium carbonate (CaCO3) which is insoluble in water. This reaction is known as a precipitation reaction.

To determine which solution contains Ca2+ ions and which contains Na+ ions, follow these steps:

Step 1: Add a few drops of the carbonate solution to one of the solutions (let's call it solution A) suspected to contain Ca2+ ions.

Step 2: Observe if a white precipitate forms. If a white precipitate is observed, it indicates the presence of Ca2+ ions.

Step 3: Now, add a few drops of the carbonate solution to the other solution (solution B) suspected to contain Na+ ions.

Step 4: Observe whether a white precipitate forms or not. If no precipitate is formed, it indicates the absence of Ca2+ ions and suggests that solution B contains Na+ ions.

In summary, the formation of a white precipitate upon the addition of the carbonate solution would indicate the presence of Ca2+ ions in solution A, while the absence of a precipitate would suggest that solution B contains Na+ ions.

To determine which solution contains Ca2+ ions and which contains Na+ ions, you can perform a simple precipitation reaction using a solution that contains CO2-3 ions (carbonate ions).

Here's what you need to do:

1. Take a small portion of each solution (containing Ca2+ ions and Na+ ions) in separate test tubes.

2. Add a few drops of the carbonate ion solution into each test tube. Carbonate ions react with certain metal ions to form insoluble precipitates.

3. Observe if a precipitate forms in either of the test tubes. If a precipitate is formed in one of the test tubes and not in the other, it indicates the presence of the corresponding metal ion.

4. In this case, if a precipitate forms in one of the test tubes, it means that the solution contains Ca2+ ions. Calcium carbonate (CaCO3) is insoluble and will form a white precipitate.

5. If no precipitate forms in either test tube, it means that neither solution contains carbonate insoluble ions. Therefore, you may need to consider using other identification methods (e.g., flame tests, complexation reactions) to determine the identity of the ions present.

By utilizing a precipitation reaction, you can differentiate between the Ca2+ and Na+ ions based on the formation of a precipitate when combined with carbonate ions.