With a chemical test differentiate between H2SO4 and H2SO3
On reaction with BaCl2 both will form a white ppt.
But in the case of H2SO3 the ppt would be soluble in HCl but not in the case of H2SO4
To differentiate between H2SO4 (sulfuric acid) and H2SO3 (sulfurous acid), you can perform a simple chemical test called the litmus test. Here are the step-by-step instructions:
Materials needed:
1. Samples of H2SO4 and H2SO3
2. Red and blue litmus paper
3. Distilled water (optional)
Procedure:
1. Obtain a small amount of each sample (H2SO4 and H2SO3) in separate containers.
2. Wet the red litmus paper by placing a drop of water on it, or moisten it slightly with distilled water.
3. Dip the red litmus paper into the sample of H2SO4, ensuring that the paper is in contact with the liquid. Observe the color change.
4. Dip the red litmus paper into the sample of H2SO3, ensuring that the paper is in contact with the liquid. Observe the color change.
5. Repeat the steps using blue litmus paper.
Interpretation of results:
- If the red litmus paper turns blue, it indicates that the sample is acidic. This means that it is a solution of H2SO4 (sulfuric acid), as it is a strong acid.
- If the litmus paper remains red or undergoes no significant change, it indicates that the sample is neutral or weakly acidic. This means it may be H2SO3 (sulfurous acid), as it is a weaker acid compared to H2SO4.
Please note that this is a basic test and may not provide definitive proof of the presence of H2SO3 or H2SO4. For precise identification, advanced analytical techniques such as titration or spectroscopy may be required.
To differentiate between H2SO4 (sulfuric acid) and H2SO3 (sulfurous acid) using a chemical test, you can use a common laboratory reagent called potassium iodide (KI) solution.
Here's how you can proceed:
1. Obtain two separate test tubes or small containers.
2. Place a small amount of the suspected H2SO4 solution in one container and the suspected H2SO3 solution in the other.
3. To each container, add a few drops of potassium iodide (KI) solution.
4. Observe the color changes that occur in each solution.
Here's what you would expect to observe:
a) H2SO4 (sulfuric acid):
When sulfuric acid reacts with potassium iodide, it oxidizes iodide ions (I-) to form elemental iodine (I2), which imparts a brown color to the solution. Thus, if the solution turns brown, it indicates the presence of sulfuric acid (H2SO4).
b) H2SO3 (sulfurous acid):
Sulfurous acid is a relatively weaker acid compared to sulfuric acid. Upon reacting with potassium iodide, sulfurous acid is not capable of oxidizing iodide ions to elemental iodine. Therefore, if no color change or a minimal color change occurs (remains colorless), it suggests the presence of sulfurous acid (H2SO3).
It's important to note that this test is not definitive, and further confirmatory tests may be required for a more accurate identification. Using additional reagents or more advanced analytical techniques, such as titration or spectroscopy, can provide a more precise determination of the acids.