› In chemistry, pH is a numeric scale used to specify the acidity or basicity (alkalinity) of an aqueous solution.
› More precisely it is the negative of the logarithm to base 10 of the activity of the hydrogen ion.
› The term pH refers to a mathematical system developed by Danish chemist Soren Sorenson (1868–1939) around 1909.
› Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic.
› Pure water is neutral, being neither an acid nor a base and its pH value is 7.
› Human blood is slightly alkaline with pH 7.3-7.5
List of ph values different household substances/items
Substance
|
PH Value
|
Battery acid
|
1.0
|
Limes
|
1.8-2.0
|
Lemon juice
|
2.2-2.4
|
Fruit jellies
|
2.8-3.4
|
Vinegar
|
2.9
|
Apple juice
|
2.9-3.3
|
Strawberries
|
3.0-3.5
|
Orange juice
|
3.7
|
Tomatoes
|
4.0-4.5
|
Bear
|
4.5
|
Coffee
|
5.0
|
Tea
|
5.5
|
Rainwater
|
5.6-6.0
|
Peas
|
5.8-6.4
|
Urine
|
6.0
|
Corn
|
6.0-6.5
|
Butter
|
6.1-6.4
|
Cow's milk
|
6.4
|
Maple syrup
|
6.5-7.0
|
Human saliva
|
6.5-7.5
|
Water
|
7.0
|
Water
|
7.0
|
Human blood
|
7.3-7.5
|
Sea water
|
7.5-8.5
|
Egg whites
|
7.6-8.0
|
Baking soda
|
8.3
|
Borax
|
9.2
|
Milk of magnesia
|
10.5
|
Laundry ammonia
|
11.0
|
Lime water
|
12.0
|
