What sort of chemical test can be performed to identify from two unlabelled powders which one is zinc hydroxide and which one is aluminium hydroxide?
Look up the determination of metals with dithizone. I believe Zn gives a colored complex when extracted into CCl4 and Al will not. But check it out.
To determine whether an unlabelled powder is zinc hydroxide or aluminium hydroxide, you can perform a chemical test using dithizone. Here's how you can proceed:
1. Look up the determination of metals with dithizone: First, search for information on the determination of metals with dithizone. This will provide you with the necessary background and procedure for conducting the test.
2. Verify if Zn gives a colored complex when extracted into CCl4: Check if the literature or reliable sources confirm that zinc hydroxide can form a colored complex with dithizone when it is extracted into carbon tetrachloride (CCl4). This complex formation indicates the presence of zinc.
3. Confirm that Al does not form a colored complex: Check if the information you found clearly states that aluminium hydroxide does not form a colored complex with dithizone when it is extracted into CCl4. This lack of complex formation suggests the absence of aluminium.
By following these steps, you will be able to determine which powder is zinc hydroxide and which one is aluminium hydroxide based on the formation or absence of a colored complex with dithizone in CCl4.