What effect does a base have on litmus paper?

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When litmus paper is exposed to a base, it changes from red to blue. This property of litmus paper is used as an indicator to test for acidity or basicity in a solution. Bases, such as sodium hydroxide or potassium hydroxide, cause the color change because they have a higher pH level, indicating a basic solution.

In this test, if the litmus paper remains red, it indicates that the solution is acidic, while a change to blue signifies that a basic solution is present. Therefore, the transformation of the litmus paper from red to blue illustrates the characteristic behavior of bases in chemical reactions.