Litmus paper - 100 pages

Slender, pocket-sized test paper strips consisting of dyed cellulose fibers. The main use of litmus is to test whether a solution is acidic or basic. Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or alkaline conditions, with the color change occurring over the pH range 4.5–8.3 at 25 °C (77 °F). Neutral litmus paper is purple.

Package Includes:

• 100pages ( 5 books each with 20 pages) in plastic container.
• Booklet: Features small sheets bound together like a tiny notebook where you tear out individual strips as needed.
• Slender gellulose fiber dyed paper strips (not reinforced).
• Select from:
• Blue Litmus Paper: Primarily used to test for acids. It stays blue in neutral or alkaline solutions but turns red/pink in acidic solutions below pH 4.5.
• Red Litmus Paper: Primarily used to test for bases. It stays red in neutral or acidic environments but turns blue in alkaline solutions above pH 8.3.
• Neutral (Purple) Litmus Paper: Infused with a blended dye. It serves as an all-in-one test by turning red for acids and blue for bases, making it perfect when you have no idea what the starting liquid is.

Please note: The litmus paper may not work on certain brands of shampoos and Sunlight Liquid dishwashing liquid as they are too close to a pH of 7. 

Sunlight: The pH of Sunlight Liquid dishwashing liquid is between 5.0 and 7.0, depending on the exact formula variant (such as Lemon or Lime). This means it ranges from slightly acidic to completely neutral. Thus we do not recommend using it in the demonstration as the exact pH is not known for each specific formulation and results will vary. If the formulation has a pH of 7 the Red Litmus paper will not turn blue.   

• Litmus Paper: Because its pH is so close to neutral (7.0) or slightly acidic, it will generally turn blue litmus paper a very faint red/pink, or cause no major color change at all if it hits exactly 7.0. Red litmus paper will remain red.
• Cabbage Juice Indicator: If you drop a diluted sample of Sunlight Liquid into purple red cabbage juice, the liquid will turn a light violet or soft purple, indicating its weak acidity/neutrality.

Demestos and Bleach: Domestos thick bleach test with litmus paper results in a unique chemical reaction, the paper will instantly flash blue and then turn completely white. Within seconds, the active ingredient in Domestos (sodium hypochlorite) destroys the plant-based pigments (lichens) that give litmus paper its color. It breaks down the chemical bonds of the dye, permanently bleaching both red and blue papers completely white.

How to see the pH before it bleaches:

• Use Universal Indicator Paper: High-quality pH strips or universal indicator paper will turn a deep violet or dark purple, which resists the bleaching effect slightly longer than basic litmus paper.
• Dilute heavily: Mix 1 drop of Domestos into a large glass of water. This dilutes the bleaching power enough for the red litmus paper to turn blue and hold its color for a bit longer before fading.

Other options for testing pH other than Litmus paper

pH Paper

How to Read pH Paper every pack of pH paper comes with a printed color-matching chart. After dipping a strip into your liquid for a few seconds, you match its color to the chart:

• Red / Dark Pink (pH 1–3): Strong Acids (e.g., Battery acid, Lemon juice)
• Orange / Yellow (pH 4–6): Weak Acids (e.g., Vinegar, Coffee)
• Green (pH 7): Neutral (e.g., Pure distilled water, Saliva)
• Blue (pH 8–11): Weak Bases (e.g., Baking soda)
• Purple / Violet (pH 12–14): Strong Bases (e.g., Domestos, Bleach, Drain cleaner)

pH Indicator Test Strips (Bottle)

pH Test Paper

Universal indicator solution is a specialized laboratory liquid mixture made from a combination of several different pH dyes. 

The Universal Indicator Color Spectrum

• Red / Deep Pink (pH 1–3): Strong Acids (e.g., Stomach acid, lemon juice)
• Orange / Yellow (pH 4–6): Weak Acids (e.g., Vinegar, black coffee, milk)
• Green (pH 7): Completely Neutral (e.g., Pure distilled water)
• Blue (pH 8–10): Weak Bases (e.g., Baking soda, sea water)
• Purple / Indigo / Violet (pH 11–14): Strong Bases (e.g., Ammonia, tile cleaner, drain cleaner)

Simple pH Test Experiment Set

Natural Plant Indicators (DIY)Many plants contain water-soluble pigments that naturally behave as pH indicators.

• Turmeric Powder: An exceptional indicator specifically for detecting strong bases. It is a bright, vibrant yellow in neutral or acidic conditions but snaps to a deep dark red-brown when it touches an alkaline substance like laundry powder or soapy water.
• Butterfly Pea Flower Tea: This herbal tea is naturally a deep blue color. If you add an acid (like a squeeze of lemon juice), it instantly turns bright purple or hot pink.
• Red Cabbage or Black Bean Juice: Both provide a broad-range universal indicator. Boiling them creates a dark liquid that changes from red (acid) to purple (neutral) to green/yellow (base).
• How to read the colors (Red Cabbage):
• Red / Dark Pink: Strong Acid (pH 1–3) Example: Lemon juice
• Light Pink / Violet: Weak Acid (pH 4–6) Example: Vinegar
• Purple: Neutral (pH 7) Example: Pure water
• Blue: Weak Base (pH 8–9) Example: Toothpaste water
• Green / Yellow-Green: Strong Base (pH 10–12) Example: Baking soda solution