Water quality information - How can you tell if a salt dissolved in water will increase or lower pH?

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REJECTION FACTS:

Change Water pH Easily - Just ADD Salt!

Bottle Water Contaminants

Water in nature is rarely pure in the "distilled water'' sense. It contains dissolved salts, buffers, nutrients, etc., with exact concentrations dependent on local conditions. Water also typically has four measurable properties that are commonly used to characterize its chemistry. They are pH, buffering capacity, general hardness and salinity. In addition, there are several nutrients and trace elements.

There is a general rule in chemistry as to how salts affect solution pH. If the salt of a strong base and weak acid is dissolved in water it will form an alkaline solution, whereas, the salt of a weak base and strong acid will form an acidic solution. The salts of a strong acid and strong base or a weak acid and weak base will both form a neutral or near neutral solution. For example, sodium sulfate (Na2SO4) will form a neutral solution when dissolved in water because it is the salt of a strong base and strong acid, whereas, tri-sodium phosphate (Na3PO4) will form an alkaline solution because it is the salt of a strong base and weak acid.

To determine whether a salt was added to a particular water, you simply need to take into account the pH of the water you seek to put the salt in. While water will not react in the exact nature as solution pH, one could expect similar results as mentioned above. When salt is added to the water, the lower the pH, the more likely the pH will increase and vice versa.