Xylenol orange is an organic reagent, most commonly used as a tetrasodium salt as an indicator for metal titrations. When used for metal titrations it will appear red in the titrand and yellow once it reaches its endpoint. Historically, commercial preparations of it have been notoriously impure, sometimes consisting of as little as 20% xylenol orange, and containing large amounts of semi-xylenol orange and iminodiacetic acid. Purities as high as 90% are now available.
Famous quotes containing the word orange:
“He hangs in shades the orange bright,
Like golden lamps in a green night,
And does in the pomegranates close
Jewels more rich than Ormus shows;
He makes the figs our mouths to meet,
And throws the melons at our feet;
But apples plants of such a price
No tree could ever bear them twice.”
—Andrew Marvell (1621–1678)