# Can I use litmus paper to test unknown liquid that contains a concentrated strong acid?

Can I use litmus paper to test unknown liquid that contains a concentrated strong acid (example $$\ce{H2SO4}$$)? Can concentrated strong acid destroy litmus paper?

• To test for concentrated sulphuric ac in such a way you can use also ham or bananas.... an unknown liquid cannot contain a concentrated acid, at most can contain a strong acid in high concentration. Regarding your last line: what destroys litmus paper and bananas is not an acid-base reaction but water withdrawal (of water already in the sample) and oxidation. Here sulphuric ac. acts as a strong oxidizer in acidic medium as well as dessicant. – Alchimista Jun 6 at 10:10