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.
For litmus, it so happens that the 50 / 50 colour does occur at close to pH 7 - that's why litmus is commonly used to test for acids and alkalis. As you will see below, that isn't true for other indicators. Methyl orange. Methyl orange is one of the indicators commonly used in titrations. In an alkaline solution, methyl orange is yellow and the structure is: Now, you might think that when you add an acid, the hydrogen ion would be picked up by the negatively charged oxygen. That's the obvious place for it to go.