Phone: (519) 746-4761

Canadian Address:

169 Lexington Court, Unit I

Waterloo, ON, N2J 4R9


US Address:

Niagara Falls, NY 14305

Canadian/International ship from Waterloo; US orders from Buffalo, NY.

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Red Litmus Paper 100 Strips/Vial

Red litmus paper turns blue when exposed to an alkaline solution; just dip a strip into the liquid & if it is basic, it will turn blue immediately; only $1.75

You can make wider/longer strips using the 200x250mm-8x10" blue litmus paper sheets which can also be used for water leak detection.

If you need more than a simple qualitative (yes or no) answer that a liquid is acidic or alkaline, we supply universal pH indicator paper sheets that are 8x10" (200x250mm).

Use pH4-5-10 test strips if you are measuring weak acids or bases since litmus paper is not very accurate between pH5.5-8.5.

SKU: 33810-RV
Red litmus paper-alkali test, 100 strips/vial

$1.75USD or lower Each

Save More When You Buy More!
Quantity1+10+ 100+ 
Price for each$1.75USD$1.60USD$1.45USD
Your savings- 8.57%17.14%
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What Turns Red Litmus Paper Blue?

The pH litmus dye chemical, 7-hydroxyphenoxazone, shown below, is extracted from lichens. You can make test solutions or paper by adding it to water or filter paper respectively. It changes from red to blue when exposed to alkaline materials (bases) such as sea water, baking soda, milk of magnesia, ammonia or oven cleaner. You can even build a physical model of 7-hydroxyphenoxazone using our 3D molecular model builder.

Litmus Dye Structure

The image shows the red litmus papers as they are available in both vial & pad; the strips are identical and turn from red to blue when dipped in an alkali (basic) solution.

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