Why does glacial acetic acid turn yellow when concentrated sulfuric acid is added?
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200 kg of glacial acetic acid was mixed with 10 kg of concentrated sulfuric acid; after being stored for a few days, it turned light yellow. It is packaged in plastic drums. What is the reason for this phenomenon? I would appreciate it if experts could provide an explanation Concentrated sulfuric acid only serves to dehydrate.
When glacial acetic acid is mixed with sulfuric acid, they form sodium acetate sulfate and sulfates; these compounds have a layer of yellow-colored ions on their surface, which causes the liquid to turn yellow.
Many colorless and transparent liquid organic substances turn yellow when mixed with other impurities.
Concentrated sulfuric acid has strong oxidizing properties and turns yellow after oxidation.
When manufacturing plastic drums, injection molding is generally used. Additives are required in both the molding molds and the molten plastic; these additives serve to enhance plasticity, improve strength, increase resistance to aging, and facilitate demolding. Some of these demolding agents may contain substances that can be dissolved by sulfuric acid or acetic acid, and they react with these acids to form colored substances. When concentrated sulfuric acid is mixed with glacial acetic acid, only a portion of the acetic acid is dehydrated to form acetic anhydride; this reaction does not produce any colored substances. Another reason might be that sulfuric acid is a bit crude and vulgar, which is why it gives a yellowish appearance.