From which plant is litmus paper or litmus solution obtained ?

(A) Moss

(B) Rose

(C) Hibiscus

(D) Lichen

Composition, Source, and Preparation of Litmus

• Composition: Litmus is a water-soluble mixture of dyes derived from lichens.
• Source: Lichens, which belong to the Thallophyta group, are the natural source of litmus.
• Process of Extraction: To prepare litmus solution, lichens are crushed and ground, and the extracted dyes are mixed with neutral water to produce the litmus solution.

Litmus Paper

• Litmus paper is made primarily from wood cellulose, like regular paper.
• During manufacturing, the wood is treated to remove resinous substances and lignin.
• The prepared paper is then infused with litmus dye (from lichens), dried, and packaged.
• This gives the paper its ability to change color when exposed to acids or bases.

Final Answer

Hence, the correct answer is (D) Lichen.

Note

• If red litmus paper does not change color in a solution, the solution is acidic.
• If blue litmus paper does not change color, the solution is basic.