-1
$\begingroup$

This question already has an answer here:

Please tell me how a pH paper works. How does it decide whether the solution is an acid or a base on the basis of ions formed and how it can determine its concentration. How does it indicate an acid or a base?

|improve this question
$\endgroup$

marked as duplicate by Jon Custer, Todd Minehardt, Freddy, ringo, Nanoputian May 14 '16 at 10:44

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

0
$\begingroup$

It's a piece of paper with one or a couple of these coated on it: https://en.wikipedia.org/wiki/PH_indicator

Indicators are dye molecules that change colour depending on the pH of a solution.

|improve this answer
$\endgroup$
  • 1
    $\begingroup$ Perhaps you could provide a little more detail here about how this works? At the moment this is in danger of being flagged as low quality for being too brief. $\endgroup$ – bon May 13 '16 at 14:29

Not the answer you're looking for? Browse other questions tagged or ask your own question.