a

b

c

d

e

f

g

h

i

j

k

l

m

n

o

p

q

r

s

t

u

v

w

x

y

z

pH

Definition

A term used to describe the hydrogen ion activity of a solution; pH= -Log (H+). For dilute solutions[H+] = molar hydrogen ion concentration. The pH of pure water is 7 and is referred to as neutral. A solution of pH less than 7 is said to be acid whereas a solution of pH above 7 is said to be alkaline. The logarithmic nature of pH means that average pH cannot be calculated from the arithmetic mean of two values.

English Greek Portuguese Swedish