Stafford, VA 22554 Quantico Corporate Center is conveniently located in Stafford, Virginia, just outside of the south gate to Quantico Marine Corps Base. Access to this eighty-five acre campus is available via US Route 1 or just seconds away from Interstate 95, exit 148.
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 4.5â8.3 at 25 Â°C (77 Â°F). Neutral litmus paper is purple. Litmus can also be prepared as an aqueous solution that functions similarly. Under acidic conditions, the solution is red, and under basic conditions, the solution is blue. Chemical reactions other than acid-base can also cause a color change to litmus paper.
If you're using litmus paper, none of this matters. The basic idea is that the paper turns a slightly different color in solutions between pH 1 and 14 and, by comparing your paper to a color chart, you can simply read off the acidity or alkalinity without worrying how many hydrogen ions there are. But a pH meter somehow has to measure the concentration of hydrogen ions.