INI
pH Scale - INI
The pH scale is a logarithmic measure of hydrogen ion concentration in aqueous solutions. Proposed in 1909 by Danish biochemist S.P.L. Sørensen, it is defined by the formula pH = -log₁₀[H⁺]. A pH of 7 is neutral, 0-6 is acidic, and 8-14 is alkaline (basic). It is widely used in chemistry, biology, agriculture, medicine, and environmental science. As a logarithmic scale where each pH unit represents a tenfold difference in hydrogen ion concentration, a change of 1 pH unit means the acidity or alkalinity changes by a factor of 10.
hydrogen ion concentration
acidity
alkalinity
basicity
chemistry
aqueous solution
logarithmic scale
[item.ph-0-strongly-acidic]
code=0
slug=ph-0-strongly-acidic
name=pH 0 (Strongly Acidic)
description=The most strongly acidic pH value.
classification=Strongly Acidic
examples=[{"name":"Hydrochloric Acid (1M)","ph":"0.0"},{"name":"Battery Acid","ph":"0.0-1.0"}]
phValue=0
[item.ph-1-gastric-acid]
code=1
slug=ph-1-gastric-acid
name=pH 1 (Gastric Acid)
description=The pH value of human gastric acid.
classification=Strongly Acidic
examples=[{"name":"Gastric Acid","ph":"1.0-2.0"}]
phValue=1
[item.ph-2-lemon-juice]
code=2
slug=ph-2-lemon-juice
name=pH 2 (Lemon Juice)
description=The pH value of citrus fruits like lemon juice.
classification=Acidic
examples=[{"name":"Lemon Juice","ph":"2.0-2.3"},{"name":"Vinegar","ph":"2.4-3.0"}]
phValue=2
[item.ph-3-orange-juice]
code=3
slug=ph-3-orange-juice
name=pH 3 (Orange Juice)
description=The pH value of orange juice and soft drinks.
classification=Acidic
examples=[{"name":"Orange Juice","ph":"3.0-4.0"},{"name":"Soft Drinks","ph":"2.5-3.5"}]
phValue=3
[item.ph-4-tomato]
code=4
slug=ph-4-tomato
name=pH 4 (Tomato)
description=The pH value of tomatoes and beer.
classification=Weakly Acidic
examples=[{"name":"Tomato","ph":"4.0-4.6"},{"name":"Beer","ph":"4.0-5.0"}]
phValue=4
[item.ph-5-coffee]
code=5
slug=ph-5-coffee
name=pH 5 (Coffee)
description=The pH value of black coffee and rainwater.
classification=Weakly Acidic
examples=[{"name":"Black Coffee","ph":"5.0"},{"name":"Rainwater","ph":"5.0-5.5"}]
phValue=5
[item.ph-6-milk]
code=6
slug=ph-6-milk
name=pH 6 (Milk)
description=The pH value of milk and saliva.
classification=Weakly Acidic
examples=[{"name":"Milk","ph":"6.5-6.8"},{"name":"Saliva","ph":"6.2-7.4"}]
phValue=6
[item.ph-7-neutral]
code=7
slug=ph-7-neutral
name=pH 7 (Neutral)
description=The pH of pure water, the boundary between acidic and alkaline.
classification=Neutral
examples=[{"name":"Pure Water","ph":"7.0"}]
phValue=7
[item.ph-8-seawater]
code=8
slug=ph-8-seawater
name=pH 8 (Seawater)
description=The pH value of seawater.
classification=Weakly Alkaline
examples=[{"name":"Seawater","ph":"8.0-8.5"}]
phValue=8
[item.ph-9-baking-soda]
code=9
slug=ph-9-baking-soda
name=pH 9 (Baking Soda)
description=The pH value of baking soda (sodium bicarbonate).
classification=Weakly Alkaline
examples=[{"name":"Baking Soda","ph":"8.3-9.0"}]
phValue=9
[item.ph-10-soap]
code=10
slug=ph-10-soap
name=pH 10 (Soap)
description=The pH value of soap and borax.
classification=Alkaline
examples=[{"name":"Soap","ph":"9.0-10.0"},{"name":"Borax","ph":"9.0-10.0"}]
phValue=10
[item.ph-11-ammonia]
code=11
slug=ph-11-ammonia
name=pH 11 (Ammonia)
description=The pH value of ammonia solution.
classification=Alkaline
examples=[{"name":"Ammonia Solution","ph":"11.0"}]
phValue=11
[item.ph-12-bleach]
code=12
slug=ph-12-bleach
name=pH 12 (Bleach)
description=The pH value of household bleach.
classification=Strongly Alkaline
examples=[{"name":"Bleach","ph":"12.0-13.0"}]
phValue=12
[item.ph-13-lye]
code=13
slug=ph-13-lye
name=pH 13 (Sodium Hydroxide)
description=The pH value of sodium hydroxide (lye/caustic soda).
classification=Strongly Alkaline
examples=[{"name":"Sodium Hydroxide (Lye)","ph":"13.0-14.0"}]
phValue=13
[item.ph-14-strongly-alkaline]
code=14
slug=ph-14-strongly-alkaline
name=pH 14 (Most Strongly Alkaline)
description=The most strongly alkaline pH value.
classification=Strongly Alkaline
examples=[{"name":"Sodium Hydroxide (1M)","ph":"14.0"}]
phValue=14