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pH

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pH

potential of hydrogen; a measure of the acidity or alkalinity of a solution equal to the common logarithm of the reciprocal of the concentration of hydrogen ions in moles per cubic decimetre of solution. Pure water has a pH of 7, acid solutions have a pH less than 7, and alkaline solutions a pH greater than 7
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

pH

[pē′āch]
(chemistry)
A term used to describe the hydrogen-ion activity of a system; it is equal to -log aH+; here aH+is the activity of the hydrogen ion; in dilute solution, activity is essentially equal to concentration and pH is defined as -log10[H+], where H+is hydrogen-ion concentration in moles per liter; a solution of pH 0 to 7 is acid, pH of 7 is neutral, pH over 7 to 14 is alkaline.

pH(S)

(analytical chemistry)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

pH

A measure of the acidity or alkalinity of a solution; numerically equal to 7.0 for a neutral solution; the pH value increases with increasing alkalinity and decreases with increasing acidity. Also See pH value.

PH

1. On drawings, abbr. for phase.
2. Abbr. for phillips head.

phot

A unit of illumination equal to 1 lumen per square centimeter. Abbr. ph.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

PH

(tool)
The tool for looking up people in Eudora on the Macintosh. Equivalent to Unix's finger service.

pH

(2)

ph

(networking)
The country code for the Philippines.
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)
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References in periodicals archive
The acidic quality of the water has also improved, after previous tests showed it measured 2 on the pH scale.
Neutral is 7 on the pH scale. Pure water is measured on the scale as having a pH of 7.0.
Because pure distilled water has the same number of hydrogen ions as hydroxyl ions, it rates a neutral 7 on a 0-14 pH scale. Despite the large amounts of water in the human body, normal pH is always slightly alkaline.
Acidity is expressed quantitatively using the pH scale. Recall that pH is calculated as:
In fact, Drano is at the opposite end of the pH scale in that the active ingredient is sodium hydroxide (NaOH), more commonly known as lye.
In this sense, beverages are a good application for natural colors because beverages tend to be on the lower pH scale. Yogurt and ice cream tend to be higher, so therefore the stability of the colors isn't going to be as long, but again, natural colors work in these applications because these products don't have a long shelf life to start."
For comparison, on the logarithmic pH scale, pure water is neutral at pH 7.0, lemon juice is pH 2.4, and a 30% sulfuric acid solution, such as battery acid, is pH -2.0.
Given that the concentrations of these ions are extremely small, scientists use the pH scale, which ranges in value from 0 to 14.
Reaction is measured by the pH scale, as shown in figure 11-1, which gives sample pH values for common substances.
THE pH scale is used to measure acidity or alkalinity of soil.
The sensors are designed for process industry applications that span the entire pH scale; have strong chemical concentrations and h igh solids; run at high temperatures and cycle from high to low temperature.
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