PH

Domain	Definitions
Computing	PH The tool for looking up people in Eudora on the Macintosh. Equivalent to Unix's finger service. (1995-03-31) pH Parallel Haskell ph The country code for the Philippines. (1999-01-27). Source: The Free On-line Dictionary of Computing.
Environment	An expression of the intensity of the basic or acid condition of a liquid; may range from 0 to 14, where 0 is the most acid and 7 is neutral. Natural waters usually have a pH between 6.5 and 8.5. (references)
Food & Agriculture	A measure of acid intensity. The pH value is the logarithm of the reciprocal of the hydrogen ion concentration. pH is neutral, values below 7 are acid and above 7 alkaline. Source: European Union. (references)
Health	The symbol relating the hydrogen ion (H+) concentration or activity of a solution to that of a given standard solution. Numerically the pH is approximately equal to the negative logarithm of H+ concentration expressed in molarity. pH 7 is neutral; above it alkalinity increases and below it acidity increases. (references)
Hydrologic	A measure of the relative acidity or alkalinity of water. Water with a pH of 7 is neutral; lower pH levels indicate increasing acidity, while pH levels higher than 7 indicate increasingly basic solutions. (references)
Mining	The negative logarithm (base 10) of the hydrogen-ion activity. It denotes the degree of acidity or of basicity of a solution. At 25 degrees C, 7 is the neutral value. Acidity increases with decreasing values below 7, andbasicity increases with increasing values above 7. (references)
Science	A symbol for the degree of acidity or alkalinity of a solution. Expressed as a negative logarithm of the hydrogen ion concentration in a solution, pH = -log10[H+]. If the hydrogen ion concentration of a solution increases, the pH will decrease, and vice versa. The value for pure distilled water is regarded as neutral, pH values from 0 to 7 indicate acidity, and from 7 to 14 indicate alkalinity. (references)
Source: compiled by the editor from various references; see credits.

Specialty Definition: Ph

ph or PH may be:

pH value
Philippines (ISO country code)
phot (ph) unit

PH

(From Wikipedia, the free Encyclopedia)

Alternate uses: see PH (disambiguation)

pH is a measure of the concentration of protons (H⁺) in a solution and, therefore, its acidity or alkalinity. The concept was introduced by S.P.L. Sørensen in 1909. The p stands for the German potenz, meaning power or concentration, and the H for the hydrogen ion (H⁺).

The formula for calculating pH is:

where [H⁺] indicates the concentration of H⁺ ions (or also written [H₃O⁺], concentration of the equivalent hydronium ions), measured in moles per litre (also known as molarity). Or in layman's terms , the " pH " value is an approximate number between 0 and 14 for the negative decimal log of the hydronium - ion concentration .

In aqueous solution at standard temperature and pressure, a pH of 7 indicates neutrality (e.g. pure water) because Water naturally disassociates into H⁺ and OH^- ions with equal concentrations of 1×10^-7M. A lower pH number (for example pH 3) indicates increasing strength of acidity, and a higher pH number (for example pH 11) indicates increasing strength of alkalinity. Most substances have a pH in the range 0 to 14, although extremely acidic or basic substances may have pH < 0, or pH > 14.

In nonaqueous solutions or non-STP conditions, the pH of neutrality may not be 7. Instead it is related to the disassociation constant for the specific solvent used.

There is also pOH, in a sense the opposite of pH, which measures the concentration of OH^- ions. Since water self ionizes, and notating [OH^-] as the concentration of hydroxide ions, we have

K_w=[H⁺][OH^-]=10^-14

where K_w is constant, the ionization constant of water.

Now, since

log K_w=log [H⁺] + log [OH^-]

by logarithmic identities, we then have the relationship

14 = log [H⁺] + log [OH^-]

and thus

pOH = log [OH^-] = 14 - log [H⁺]

Some common aqueous pH's

3.5: orange juice (slightly acidic)
5.6: unpolluted rain water (slightly acidic)
7.0: pure water
7.34 - 7.45: human blood (slightly alkaline)
11.0: household ammonia (very alkaline)

Measuring

pH can be measured by addition of a pH indicator or using a pH meter. Universal Indicator changes colour depending on the pH of the solution it is added to. Electronic pH meters consist of an electrolytic cell in which an electric current is created due to the hydrogen cations completing the circuit.

Calculation of pH for weak and strong acids

Values of pH for weak and strong acids can be approximated using certain assumptions. It is assumed that for strong acids, the dissociation reaction goes to completion (i.e., no unreacted acid remains in solution). Dissolving the strong acid HCl in water can therefore be expressed:

HCl(aq) → H⁺ + Cl^-

This means that in a 0.01 M solution of HCl it is approximated that there is a concentration of 0.01 M dissolved hydrogen ions. From above, the pH is: pH = -log₁₀ [H⁺(aq)]:

pH = -log(0.01)

which equals 2.

For weak acids the dissociation reaction does not go to completion, an equlibrium is set up between the ions and the acid. The following shows the equilibrium reaction between methanoic acid and its ions:

HCOOH(aq) ↔ H⁺(aq) + HCOO^-(aq)

It is necessary to know the value of the equilibrium constant of the reaction for each acid in order to calculate its pH. In the context of pH, this is termed the acidity constant of the acid but is worked out in the same way (see chemical equilibrium):

K_a = [hydrogen ions (aq)][acid ions (aq)] / [acid (aq)]

For HCOOH, K_a = 1.6 × 10^-4

Two assumptions are made in the calculation of pH for a weak acid. It is assumed that the water the acid is dissolved in does not provide any hydrogen ions. Water is a very weak acid and in general it supplies far fewer than the acid dissolved in it. Consequently in the above reaction the concentration of hydrogen ions equals the concentration of methanoate ions:

[H^-(aq)] = [HCOO^-(aq)]

It is also taken that the amount of undissociated acid at equilibrium is equal to the amount originally added to the solution. Although this is obviously untrue (otherwise the pH would remain 7!) this amount can be neglected because the fraction of hydrogen ions given is again very small.

With a 0.1 M solution of methanoic acid (HCOOH), the acidity constant is equal to:

K_a = [H⁺(aq)][HCOO^-(aq)] / [HCOOH(aq)]

So:

1.6 × 10^-4 = [H⁺][HCOO^-] / 0.1

1.6 × 10^-4 × 0.1 =[H⁺][HCOO^-]

As [H^-(aq)] = [HCOO^-(aq)]:

1.6 × 10^-4 × 0.1 =[H⁺]²

The concentration of hydrogen ions is: 4 × 10^-3. The pH, therefore, is: 2.3.

See also: Acid-base reaction theories, Acid, Base, Alkali, Soil pH, titration

Abbreviations & Acronyms: PH

The following table is compiled from various sources, across various languages. When English abbreviations or acronyms come from a non-English source, this is noted.
Entry	Source	Expression	Field
PH	Danish	Filippinerne	Geography
pH	Dutch	Zuurgehalte	Chemistry
PH	English	Physical layer	N/A
PH	Finnish	Filippiinit	Geography
PH	French	Pneumopathies d'hypersensibilité	N/A
pH	German	Potenz des Hydrogeniums	Chemistry
PH	Greek	Φιλιππίνες	Geography
PH	Italian	Filippine	Geography
pH	Latin	Potentia hydrogenii	Chemistry
PH	Portuguese	Valor de acidez	Chemistry
PH	Spanish	Filipinas	Geography
PH	Swedish	Filippinerna	Geography
pH(S)	English	Standard pH scale	Electrical Engineering
Source: compiled by the editor, based on several corpora (additional references).

Modern Usage: PH

Commercial Usage: PH

Photo Album: PH

Thumbnail	Description & Credit	Thumbnail	Description & Credit
	David Satcher, M.D., Ph.D., Director, CDC, 1994. Dr. Satcher accepted appointment as U.S. Surgeon General in 1998.Credit: CDC.		Treatment plant at Minnesota Flats to treat AMD from the Richmond and Lawson Portals. Water raised PH 1 - 11 to ppt sludge. The sludge was hauled to Brick Flat pit.Credit: NOAA Restoration Center.
	Flume of PH 1 water from portals no longer in use, Richmond and Lawson, at Iron Mountain Mine.Credit: NOAA Restoration Center.		Figure 63. Sorensen device for the determination of H+ ions. This device which measured the pH of water by a colorimetric method was devised by the Danish chemists Soren Peter Lauritz Sorensen and Sven Palitsch and used during the Danish oceanographic expedition on the THOR between 1908 and 1910.Credit: Sailing for Science - the NOAA Fleet Then and Now.
	All the soils in Iowa have been surveyed and cataloged as part of the cooperative soil survey program by the state of Iowa, Iowa State University, and the USDA Natural Resources Conservation Service. Soil pH is one of the items in the soils database peopl.Credit: Tim McCabe.		Shauna Russell from the Holston Soil and Water Conservation District obtaining water temperature and Ph and part of water quality testing. Virginia.Credit: Jeff Vanuga.
	Drum of hazardous chemical, pH 14, found in Mill buildingTwin Peak MineSalmon Field OfficeUCSCUpper Columbia Salmon Clearwater District.Credit: Tim Geary.		Almeda Mine, Medford District. Testing pH.Credit: John Craig.
	Acrylic painting of a spectacled eider flying over an Arctic seascape by Joseph Hautman, 410 Sycamore Circle, Plymouth, MN 55441. Hautman's design was one of 585 entered in the 1991 Federal Duck Stamp Contest. He studied art and physics at the University of Minnesota where he received a degree in physics and later received a Ph.D. in physics from the University of Michigan. His published work has contributed to the understanding of a broad range of phenomenon -- from the shapes of water droplets and snow flakes to the miscroscopic structures of soap bubbles and cell membranes. Return to the Federal Duck Stamp Office Home Page.		Del'orgéat pour un rhume? / Ch Ph. [Monogram].Credit: National Library of Medicine.
Source: compiled by the editor from various references; see credits.

Non-Fiction Usage: PH

Subject	Topic	Quote
Health		Dennis W. Choi, M.D, Ph.D.Department of Neurology, Box 8111School of MedicineWashington University660 South Euclid AvenueSt. (references)
		Chemical disinfection may be less effective than other methods because it is highly dependent on the temperature, pH, and cloudiness of the water. (references)
		Electrophoresis at alkaline pH on cellulose acetate followed by further examination of abnormal samples by acid electrophoresis on citrate agar is presently the most popular procedure used for mass screening. (references)
Business		Of these, 72 researchers have a Ph.D., 152 have an MS, and 66 have a BS degree. (references)
		Only 2% working in IT have a Ph.D. while 26% claim to have some kind of a diploma. (references)
		The best prospects include reagents, research distillers, water baths, sterilizers, auto cloves, pH meters, hot plates, microscopes, balances, centrifuges among others. (references)
Civil Liberties	Jordan	On March 19, riot police protecting the Prime Ministry used physical force, including batons, to disperse a sit-in by 25 Ph.D. holders. (references)
Economic History	Malaysia	Malaysia continues to import much of its water-wastewater treatment chemicals, such as pH adjusters and alkali-based chemicals, since local producers can provide only the basic chemicals. (references)
	Barbados	CHELTENHAM, Dr. Richard L., Q.C., Ph.D. "Charlton House," Whitepark Road, St. Michael, Tel: 246/431-0291, Fax: 246/431-0143. Citizen of Barbados. (references)
Source: compiled by the editor from ICON Group International, Inc.; see credits.

Spoken Usage: PH

Usage Frequency: PH

Usage in Company Names: PH

Expressions: PH

Frequency of Internet Keywords: PH

Modern Translations: PH

Language		Translations for "pH"; alternative meanings/domain in parentheses.
Chinese		酸碱度. (various references)

Danish		pH (acid value, pH value, Philippines, pH-value, Republic of the Philippines). (various references)

Dutch		pH (acid value, hydrogen ion concentration, pH value, Philippines, pH-value, Republic of the Philippines). (various references)

Finnish		pH-arvo (acid value, pH value, pH-value), pH (acid value, pH value, Philippines, pH-value, Republic of the Philippines), vetyioni konsentraatio (hydrogen ion concentration). (various references)

French		potentiel Hydrogène (pH value, pH-value), pH acidité réelle, pH (pH value, Philippines, Philippines-ISO code, phrase, pH-value, Republic of the Philippines), valeur pH (pH value, pH-value), concentration plasmatique d'ions H+,pH, acidité ionique (pH value, pH-value). (various references)

German		pH (acid value, pH value, Philippines, phot, phrase, pH-value, Republic of the Philippines). (various references)

Greek		PH,βαθμός οξύτητας. (various references)

Italian		pH (acid value, pH value, Philippines, phot, pH-value, Republic of the Philippines). (various references)

Japanese Kanji		ページ組み (concentration of hydrogen ions, pace, pacemaker, paging, paper, paper chromatography, paper company, paper holder, paper plan, paperback, papercraft, paste, pathos, person with driving licence but no practice, pest, written test), 液性 (humoral). (various references)

Japanese Katakana		ペーハー (concentration of hydrogen ions), えきせい (humoral, many generations). (various references)

Pig Latin		phay

Portuguese		pH (Philippines, Republic of the Philippines). (various references)

Spanish		pH (acid value, pH value, Philippines, phot, pH-value, Republic of the Philippines), valor del pH (acid value, pH value, pH-value), valor de acidez (acid value, pH value, pH-value), energía ácida, acidez actual. (various references)

Swedish		pH-värde (acid value, pH value, pH-value), pH (Philippines, Republic of the Philippines). (various references)
Source: compiled by the editor from various translation references.

Ancestral Language Translations: PH

Derivations: PH

Derivations
	Words beginning with "pH": phaeton, phaetons, phage, phages, phagocyte, phagocytes, phagocytic, phagocytize, phagocytized, phagocytizes, phagocytizing, phagocytose, phagocytosed, phagocytoses, phagocytosing, phagocytosis, phagocytotic, phalange, phalangeal, phalanger, phalangers, phalanges, phalansteries, phalanstery, phalanx, phalanxes, phalarope, phalaropes, phalli, phallic, phallically, phallicism, phallicisms, phallism, phallisms, phallist, phallists, phallocentric, phallus, phalluses, phanerogam, phanerogams, phanerophyte, phanerophytes, phantasied, phantasies, phantasm, phantasma, phantasmagoria, phantasmagorias, phantasmagoric. (additional references)
	Words ending with "pH": acaleph, aleph, allelomorph, allograph, allomorph, anaglyph, anemograph, anthropomorph, astrophotograph, autograph, autoradiograph, autotroph, auxotroph, barograph, bathyscaph, bathythermograph, bimorph, bumph, caliph, caph, cardiograph, cenotaph, ceriph, choreograph, chromatograph, chromolithograph, chronograph, cinematograph, coronagraph, coronograph, cryptograph, diagraph, digraph, dimorph, ectomorph, electrocardiograph, electroencephalograph, electromyograph, electroretinograph, enantiomorph, encephalograph, endolymph, endomorph, epigraph, epitaph, ergograph, galumph, glyph, gonoph, graph, gynandromorph. (additional references)
	Words containing "pH": acalephae, acalephe, acalephes, acalephs, acanthocephalan, acanthocephalans, acephalous, acetaminophen, acetaminophens, acetophenetidin, acetophenetidins, acidophil, acidophile, acidophiles, acidophilic, acidophils, acrophobe, acrophobes, acrophobia, acrophobias, actinomorphic, actinomorphies, actinomorphy, adenohypophyseal, adenohypophyses, adenohypophysial, adenohypophysis, adrenocorticotrophic, adrenocorticotrophin, adrenocorticotrophins, agoraphobe, agoraphobes, agoraphobia, agoraphobias, agoraphobic, agoraphobics, agrapha, agraphia, agraphias, agraphic, ailurophile, ailurophiles, ailurophobe, ailurophobes, ailurophobia, ailurophobias, alephs, aliphatic, allelomorphic, allelomorphism, allelomorphisms. (additional references)
Source: compiled by the editor, based on several corpora (additional references).

Anagrams: PH

Scrabble® Enable2K-Verified Anagrams
	Words containing the letters "h-p"
	+1 letter: hap, hep, hip, hop, hup, hyp, pah, peh, phi, pht, poh.
	+2 letters: caph, chap, chip, chop, epha, haps, harp, hasp, heap, help, hemp, hips, holp, hoop, hope, hops, hump, hype, hypo, hyps, kaph, koph, opah, ouph, pash, path, pech, pehs, phat, phew, phis, phiz, phon, phot, phut, pish, pith, pooh, posh, pugh, push, qoph, ship, shop, soph, syph, toph, whap, whip, whop.
Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro.

Domain	Title
Books	Fundamentals of Financial Management and PH Finance Center CD (11th Edition) (reference) (more book examples)
Source: compiled by the editor from various references; see credits.

Speaker	Phrase(s)
James Dobson	That's not really new. When I got my Ph.D. at USC, that's what everybody was talking about it. Get them out of the home, get them into early education. It just hasn't panned out. Made real problems.
Source: compiled by the editor from various references; see credits.

Parts of Speech	Percent	Usage per 100 Million Words	Rank in English
Noun (singular)	98.84%	1,527	5,354
Unclassified Items	1.16%	18	82,615
Total	100.00%	1,545	N/A

Country	Name
USA	PH Group Inc.
	(more examples...)

Expressions using "pH": Citra pH ♦ Esophageal Ph Monitoring ♦ esophageal pH test ♦ oesophageal pH monitoring ♦ oesophageal pH test ♦ Ph D ♦ pH junctions ♦ Ph lunatus ♦ Ph maltiflorus ♦ pH scale ♦ pH value ♦ Ph vulgaris ♦ standard pH scale ♦ surface pH ♦ ultimate pH. Additional references.
Hyphenated Usage
	Beginning with "pH": pH-acidometer, PH-ACTIVATE, ph-changing, PH-DATA, pH-meter, ph-metry, ph-sensitive, pH-value.
	Ending with "pH": eh-ph, oesophageal-ph.
Source: compiled by the editor from various references; see credits.

Expression	Frequency per Day	Expression	Frequency per Day
ph	953	ph electrode	28
ph meter	253	blood ph	27
ph scale	179	ph factor	24
ph balance	101	ph value	24
ph level	87	ph chart	23
ph tester	87	ph school	23
ph miracle	78	d ph	23
ph test	65	urine ph	22
soil ph	56	el es ph que	22
ph paper	44	swimming pool ph	21
ph of water	43	ph indicator	20
ph testing	34	ph analyzer	20
ph sensor	34	definition ph	19
pool ph	34	soil ph meter	19
ph probe	32	harry order ph potter	19
body ph	29	ph controller	18
in intestine ph	29	ph quant satinover	17
ph test strip	28	pond ph	16
ph strip	28	food ph	16
ph buffer	28	orion ph meter	15
Source: compiled by the editor from various references; see credits.

Language	Period	Translations
Latin	500 BCE-Modern	potentia hydrogenii. (various references)
German	100 BCE-Modern	Potenz. (various references)
Source: compiled by the editor from various references.

PH

Definition: PH

PH

Noun

Specialty Definitions: PH

Specialty Definition: Ph

PH

Some common aqueous pH's

Measuring

Abbreviations & Acronyms: PH

PH

pH

PH

PH

PH

pH

PH

PH

pH

PH

PH

PH

Synonym: PH

Crosswords: PH

Modern Usage: PH

Movie/TV Titles

Commercial Usage: PH

Books

Photo Album: PH

Non-Fiction Usage: PH

Spoken Usage: PH

James Dobson

Usage Frequency: PH

Usage in Company Names: PH

PH Group Inc.

Expressions: PH

Frequency of Internet Keywords: PH

Modern Translations: PH

Chinese

Danish

Dutch

Finnish

French

German

Greek

Italian

Japanese Kanji

Japanese Katakana

Pig Latin

Portuguese

Spanish

Swedish

Ancestral Language Translations: PH

Derivations: PH

Derivations

Anagrams: PH

Scrabble® Enable2K-Verified Anagrams

Alternative Orthography: PH

50 48

.--. ....

Bibliographic Items: "pH"

Public Service or Web Sites Triggered by: PH