What would be the difference in how you would test vinegar and soap with litmus paper?

To test vinegar with litmus paper, you would use red litmus paper, which should remain red, confirming its acidic nature (pH around 2-3). In contrast, when testing soap, you would use blue litmus paper, which should remain blue, indicating its basic or alkaline properties (pH typically above 7). If you were to use red litmus paper on soap, it would turn blue, further confirming its basicity.