Question

what are the practical application of indicators​

Answer 1

Answer:

Testing the acidity or basicity of soils, as some plants grow best in slightly acidic soils (such as azaleas and pineapples) while others grow best in slightly basic soils

Answer 2

Answer:

plz Mrk as brainliest dear

Chemical indicator, any substance that gives a visible sign, usually by a colour change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow colour to an alkaline solution. If acid is slowly added, the solution remains yellow until all the alkali has been neutralized, whereupon the colour suddenly changes to red.

Like most indicators, methyl yellow is visible even if its concentration is as low as a few parts per million parts of solution. Used at such low concentrations, indicators do not have any influence on the conditions for which they are recommended. The common application of indicators is the detection of end points of titrations.

The colour of an indicator alters when the acidity or the oxidizing strength of the solution, or the concentration of a certain chemical species, reaches a critical range of values. Indicators are therefore classified as acid-base, oxidation-reduction, or specific-substance indicators, every indicator in each class having a characteristic transition range. Methyl yellow, an acid-base indicator, is yellow if the hydrogen ion (acid) concentration of the solution is less than 0.0001 mole per litre and is red if the concentration exceeds 0.0001. Ferrous 1,10-phenanthroline, an oxidation-reduction indicator, changes from red to pale blue when the oxidation potential of the solution is increased from 1.04 to 1.08 volts; and diphenylcarbazone, an indicator for mercuric ion, changes from yellow to violet when the mercuric ion concentration is increased from 0.000001 to 0.00001 mole per litre. Each of these indicators thus has a relatively narrow transition range, and each is capable of giving a sensitive, sharp indication of the completion of a reaction, that is, the end point.