# Will strong concentrated acid destroy litmus paper and pH paper if they are dipped in acid?

I am curious to know what will happen if I have litmus paper and pH paper, and I dip them into strong concentrated acid like conc. $$\ce{H2SO4}$$ to test its acidity or basicity. Will acid destroy papers? if YES, then how will I determine the acidity? do I need something else to carry my experiment?

• There are $\mathrm{pH}$ meters too, unless you're also concerned about dissolving glass electrodes. – William R. Ebenezer Jun 5 at 4:14
• Side note: never dip paper indicators into the solution; this is a waste of material (more paper is soaked) and introduces impurities (indicator, cellulose fibers, dust etc.) into the batch. Instead, put a glass stick in a thoroughly mixed solution, then touch the paper strip with the tip of the glass stick. – andselisk Jun 5 at 4:59
• What is the sense in testing acidity of concentrated sulphuric acid in the first place ? – Poutnik Jun 5 at 9:26

Liquid pH testing solutions or drops are also available. Other indicators like phenolphthalein, methyl orange , methyl red can be used if you expect your test solution to fall in the pH range of the respective indicators. Also it will be wise to take a small sample of the solution to test it rather than testing the whole thing.

• Doesn't this answer circumvent the main question? – William R. Ebenezer Jun 5 at 11:07