pH

1 of 2

noun

ˈpē-ˈāch 

: a measure of acidity and alkalinity of a solution that is a number on a scale on which a value of 7 represents neutrality and lower numbers indicate increasing acidity and higher numbers increasing alkalinity and on which each unit of change represents a tenfold change in acidity or alkalinity and that is the negative logarithm of the effective hydrogen-ion concentration or hydrogen-ion activity in gram equivalents per liter of the solution

also : the condition represented by a pH number

PH

2 of 2

abbreviation

1

pinch hit

2

public health

3

Purple Heart

Examples of pH in a Sentence

Recent Examples on the Web

Noun

Soil pH is defined as the acidity or alkalinity of the soil. —Rita Perwich, San Diego Union-Tribune, 4 Nov. 2023

That is, assuming the watering issue, pH, sun and everything else is right. —oregonlive, 16 Sep. 2023

Sensors constantly monitor the pH, auto-adjust the temperature, and instantly detect issues like botulism, then send information back to an app on your phone. —Ali Francis, Bon Appétit, 15 Aug. 2023

According to Pauline Jose, MD, a clinical instructor at UCLA and founder of pH Drip Lab, this is standard practice. —Ariana Yaptangco, Glamour, 31 July 2023

These cables carry sensors to measure water temperature and sea currents, as well as oxygen and pH levels. —Dhananjay Khadilkar, Ars Technica, 31 Mar. 2023

Those extreme conditions, according to cosmetic chemist Krupa Koestline, include salinity, pH, drought, temperature, and irradiation. —Marci Robin, Allure, 29 Mar. 2023

This suggests the parasite decline may be associated with climate change, though the researchers say additional factors, such as ocean pH or algal blooms, could have contributed as well. —Teresa Nowakowski, Smithsonian Magazine, 17 Jan. 2023

Powered by a cocktail of AHAs, BHA, PHA, vitamin B3, and horseradish extract, this is lauded for its ability to balance your skin’s pH and erase dark spots. —Kiana Murden, Vogue, 1 Sep. 2022

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Word History

Etymology

Noun

German, from Potenz power + H (symbol for hydrogen)

First Known Use

Noun

1909, in the meaning defined above

Phrases Containing pH

• pH meter

• pH meter

Kids Definition

pH

noun

(ˈ)pē-ˈāch 

: a number used in expressing acidity or alkalinity on a scale whose values run from 0 to 14 with 7 representing neutrality, numbers less than 7 increasing acidity, and numbers greater than 7 increasing alkalinity

also : the condition represented by such a number

Medical Definition

ph

1 of 2 abbreviation

1

pharmacopoeia

2

phosphor

3

phot

pH

2 of 2 noun

(ˈ)pē-ˈāch 

: a measure of acidity and alkalinity of a solution that is a number on a scale on which a value of 7 represents neutrality and lower numbers indicate increasing acidity and higher numbers increasing alkalinity and on which each unit of change represents a tenfold change in acidity or alkalinity and that is the negative logarithm of the effective hydrogen-ion concentration or hydrogen-ion activity in gram equivalents per liter of the solution

instead of saying that the concentration of hydrogen ion in pure water is 1.00 x 10⁻⁷, it is customary to say that the pH of pure water is 7

—Linus Pauling

also : the condition represented by such a number compare pk