Methyl Orange - Indicator Colours

Indicator Colours

Methyl orange (pH indicator)
below pH 3.1 above pH 4.4
3.1 ↔ 4.4
Methyl orange in xylene cyanol solution (pH indicator)
below pH 3.2 above pH 4.2
3.2 ↔ 4.2

In a solution becoming less acidic, methyl orange moves from red to orange and finally to yellow with the reverse occurring for a solution increasing in acidity. The entire colour change occurs in acidic conditions.

In an acid it is reddish and in alkali it is yellow. Methyl orange has a pKa of 3.47 in water at 25 degrees Celsius.

Read more about this topic:  Methyl Orange

Famous quotes containing the word colours:

    “When we reflect on our past sentiments and affections, our thought is a faithful mirror, and copies its objects truly; but the colours which it employs are faint and dull, in comparison of those in which our original perceptions were clothed.”
    —David Hume (1711–1776)