What Color Does Litmus Paper Turn in Acid?
Last Updated Apr 7, 2020 5:54:56 AM ET

When blue litmus paper is dipped in an acid, it turns red; when red litmus paper is dipped in an acid, it just appears to get wet. Alkacid paper, which is a universal indicator, turns orange or red when it is reacting to an acid, with a redder color indicating a lower pH and a stronger level of acidity.
It is important to use both red and blue litmus paper when testing a substance. If the substance is neutral, it just makes the red litmus paper look wet. If that same neutral substance is tested on blue litmus paper, it again makes the paper just appear wet (or a slightly darker blue) rather than turning the blue litmus paper red, as an acidic substance does.
More From Reference

How Do You Apply for Social Security Benefits?

How Did the VW Beetle Become an Emblem of the '60s?

We Explain the Complicated History of Myanmar and Aung San Suu Kyi

Financing the Future: Setting Up Savings Plans for Grandchildren

Responsible Retirement: What's the Maximum Amount You Can Contribute to a 401(k)?

10 Small Business Grants for Women Entrepreneurs