how can you differentiate between oxalic acid, citric acid and tartaric acid with CaCl2 test? show the chemical reaction?
Look at the possible products:
calcium citrate, calcium oxalate, and calcium tartrate.
Are any of those insoluble in water? If so, a precipitate is formed. One of them is a problem in my making homemade wines.
The CaCl2 test can be used to differentiate between oxalic acid, citric acid, and tartaric acid based on the formation of precipitates. Here's how you can perform the test and the chemical reactions involved:
1. Prepare separate solutions of oxalic acid, citric acid, and tartaric acid in water. Make sure the concentrations of the solutions are the same.
2. Take three test tubes and label them as A, B, and C, corresponding to oxalic acid, citric acid, and tartaric acid, respectively.
3. In each test tube, add an equal volume of the respective acid solution. For example, if you add 1 mL of oxalic acid solution to test tube A, add 1 mL of citric acid solution to test tube B, and 1 mL of tartaric acid solution to test tube C.
4. To each test tube, add a few drops of calcium chloride solution (CaCl2). The calcium chloride reacts with the acid to form a precipitate if the acid is present.
The chemical reactions involved in the CaCl2 test with each acid are as follows:
Oxalic Acid:
C2H2O4 (aq) + CaCl2 (aq) → CaC2O4 (s) + 2HCl (aq)
Citric Acid:
C6H8O7 (aq) + 3CaCl2 (aq) → 3CaC6H5O7 (s) + 6HCl (aq)
Tartaric Acid:
C4H6O6 (aq) + 2CaCl2 (aq) → CaC4H4O6 (s) + 2CaCl (aq) + 2HCl (aq)
After adding CaCl2, you will observe different precipitates in the test tubes:
- If a white precipitate forms in test tube A, it indicates the presence of oxalic acid.
- If a white precipitate forms in test tube B, it indicates the presence of citric acid.
- If a white precipitate forms in test tube C, it indicates the presence of tartaric acid.
By comparing the results with the known reactions, you can differentiate between oxalic acid, citric acid, and tartaric acid using the CaCl2 test.