Ph Indicators And Solution

pH Indicators generally are weakly acidic, halochromic chemical compounds that are used in estimation of a solution's pH value by providing an indication about the concentration of Hydrogen (Hydronium) ions in the solution via change in color. The negative logarithm of this concentration can be used to determine the value of actual value of acidity or basicity of a solution on the pH scale, between the values of 0-14. Liquid based pH indicators are added directly to the test solution in estimation of the aforesaid value via hue change, with each color representing a specific range of acidity/basicity and corresponds to an approximate value on the pH scale.

1) The color change observed in the solution on addition of the indicator is due to the dissociation of a Hydrogen ion/proton from the very indicator, thanks to their weakly acidic nature.
2) Different pH indicators are sensitive or show their signature color change to a particular value of pH or hydrogen ion concentration in a solution and have their own range.
3) Universal indicators are a special class of indicators whose pH sensitivity range is much greater, and consequently, the spectrum of color change is considerably broader.
4) One of the most commonly known area of their application is in titration in analytical chemistry, and also in determination of extent of a reaction in studying certain biological processes.