Question #61c95

1 Answer
Jun 2, 2016

There are a myriad of chemicals used to test water potability.

Explanation:

A simple series of chemical tests should not be taken as an all-encompassing panacea in determining water potability, there are too many other variables (many nasty bacteria, viruses, and protozoan live in muddy or dirty water which does not need to be stagnant to harbor "nasties") that are not detected by chemical testing that need to be taken into account. I'll attempt to compile a list of the chemicals used to test water potability, by no means will it be exhaustive.

Without further ado I present to you --the list:

Methylene Blue, Boric Acid, and Chloroform- a common pH indicator, methylene blue when mixed with boric acid and chloroform can help detect surfactants (detergents, emulsifiers, foaming agents, and dispersants) such as carboxylates, phosphates, and sulfonates (however the results are non-specific, all the test tells us is that a surfactant is present); this test is called the methylene blue active substances assay (MBAS assay)

Silver Nitrate, Sodium Chloride- Silver nitrate is a key chemical in photography (a chemical used in developing pictures), sodium chloride is what makes my blood pressure climb through the roof (table salt), used individually these chemicals detect chloride in water sources

Bromocresol Green and Methyl Red (phenolphthalein)- are both common pH indicators, in regard to water testing they are mixed to form a common indicator and are used to detect alkalinity (the pH) of the water

Sodium Hydrosulfite- is a chemical utilized in water testing to detect the presence of copper, sodium hydrosulfite can be used in manufacturing leather and polymers however it is highly toxic and rarely used in such industries

Potassium Hydroxide- is used in a laboratory setting as a desiccant however in water analysis it is used to test for water "hardness" (the amount of calcium and magnesium dissolved in the water)

Sulfate and Sodium Thiosulfate- sodium thiosulfate has many medical uses acting as an antidote for cyanide poisoning and as an antifungal agent, while sulfate is a fairly ubiquitous chemical with numerous uses in manufacturing, both of these chemicals are used (individually) in detecting the presence of hydrogen peroxide

Potassium Persulfate, Sodium Hydroxide, and Sulfuric Acid- potassium persulfate is a powerful oxidant and is used in the manufacturing of polymers, sodium hydroxide (also known as lye) is a caustic base used in making paper, soap, textiles, and drain cleaners (drain-o anyone?), sulfuric acid is a byproduct of coal and gas fueled power plants and industrial manufacturing it is a primary component of acid rain, all of these chemicals used individually detect phosphates in water supplies

Citric Acid and Molybdate- citric acid (also known as vitamin C) prevents you from getting scurvy (and talking like a pirate!), molybdate is used in a laboratory setting as a catalyst for reactions, both of these chemicals individually detect silica in water sources

I hope this helped!