Definition of litmus paper in US English:

litmus paper


  • Paper stained with litmus which is used to indicate the acidity or alkalinity of a substance. Blue litmus paper turns red under acid conditions, and red litmus paper turns blue under alkaline conditions.

    • ‘Earth's greatest scientists work around the clock to avert disaster, finally resolving the problem with the careful use of test tubes, Bunsen burners, and litmus paper.’
    • ‘A few weeks later, so did the litmus paper in one of his urine tests.’
    • ‘To test pH, you can get a digital meter for about $50, or you can get litmus paper or a dropper kit like the ones used for pools.’
    • ‘Contrast the two general statements: that blue litmus paper dipped in acid turns red; and that all the coins in my pocket are pound coins.’
    • ‘Blue litmus paper turns red in acidic solution, and red litmus paper turns blue in basic solution.’
    • ‘Consider a case in which the law ‘all blue litmus paper turns red in acid solution’ is tested by placing a piece of paper in a liquid.’
    • ‘Acids are typically corrosive, sour to the taste, turn litmus paper red, react with some metals to liberate hydrogen, and neutralize bases.’
    • ‘We might, for example, give up the claim that this liquid is an acid, or the claim that this is a piece of litmus paper, or the claim we are not hallucinating, etc.’
    • ‘A litmus paper can be used to find out whether the soil is acidic, alkaline or neutral.’
    • ‘‘The litmus paper is still the litmus paper,’ he enunciated in the formal manner of the lecturer.’
    • ‘The law, therefore, is unreliable sociological litmus paper.’
    • ‘When adequately lavaged use litmus paper to ensure that eye pH is neutral immediately after the lavage is completed and again 10 minutes later.’
    • ‘Test pH with an inexpensive soil testing kit available at hardware and lawn and garden centers, or with litmus paper sold at drugstores.’
    • ‘Making litmus paper change colour was uninspiring and dissecting enormous rats was a lesson more steeped in butchery than anatomy.’


litmus paper

/ˈlitməs ˌpāpər/