pH
VALUES :-
The acidity or alkalinity of solution
is expressed by its pH value. A neutral solution such as water
has a pH value of 7.0 Decreasing pH values from 7.0 to 0.0
indicate increasing acidity and increasing pH value 7.0 to
14.0 indicate increasing alkalinity. Since the pH value denotes
the acidity or alkalinity of a liquid it gives some indication
of the materials required in constructiing a pump to handle
the liquid. The pH value alone, however, is not conclusive.
Many other factors must be considered. However, as a guide,
the following tables give approximately pH values.
MATERIALS OF CONSTRUCTION
INDICATED BY pH VALUE
pH value |
Material
of Construction |
0 to 4 |
Corrosion Resistant Alloys Steels. |
4 to 6 |
All Bronze. |
6 to 8 |
Bronze Fitted or Standard Fitted. |
8 to 10 |
All Iron |
10 to 14 |
Corrosion Resistant Alloys. |
APPROXIMATE pH VALUES
ACIDS |
Hydrochloric, N |
0.1 |
Hydrochloric,
0.1N |
1.1 |
Hydrochloric,
0.01N |
2.0 |
Sulfuric,
N |
0.3 |
Sulfuric, 0.1N |
1.2 |
Sulfuric, 0.01N
|
2.1 |
Orthophosphoric,
0.1N |
1.5 |
Sulfurous,
0.1N |
1.5 |
Oxalic, 0.1N |
1.6 |
Tartaric 0.1N |
2.2 |
Malic. 0.1N |
2.2 |
Citric, 0.1N |
2.2 |
Formic, 0.1N |
2.3 |
Lactic, 0.1N |
2.4 |
Acetic, N |
2.4 |
Acetic, 0.1N |
2.9 |
Acetic, 0.01N |
3.4 |
Benzoic,
0.01N |
3.1 |
Aoum, 0.1N |
3.2 |
Carbonic (saturated) |
3.8 |
Hydrogen sulfide, 0.1N |
4.1 |
Arsenious (saturated) |
5.0 |
Hydrocyanic, 0.1N |
5.1 |
Boric, 0.1N |
5.2 |
|
BASES |
Sodium hydroxide, N |
14.0 |
Sodium hydroxide, 0.1N |
13.0 |
Sodium hydroxide, 0.01N |
12.0 |
Potassium
hydroxide, N |
14.0 |
Potassium
hydroxide, 0. 1N |
13.0 |
Potassium
hydroxide, 0.01N |
12.0 |
Sodium
metasilicate, 0.1N |
12.6 |
Lime (saturated) |
12.4 |
Trisodium phosphate, 0.1N |
12.0 |
Sodium carbonate, 0.1N |
11.6 |
Calcium Carbonate (saturated) |
9.4 |
Ammonia,
N |
11.6 |
Ammonia, 0.1N |
10.6 |
Ammonia, 0.01N |
11.0 |
Potassium cyanide, 0.1N |
10.5 |
Magnesia (saturated) |
10.1 |
Sodium sesquicarbonate, 0.1N |
9.5 |
Ferrous hydroxide. (saturated) |
9.4 |
Borax,
0.1N |
9.2 |
Sodium bicarbonate, 0.1N |
8.4 |
BIOLOGICAL MATERIALS |
Blood, plasma, human |
7.3-7.5 |
Spinal fluid, human |
7.3-7.5 |
Blood, whole dog |
6.9-7.2 |
Saliva, human |
6.5-7.5 |
Gastric contents, human |
1.0-3.0 |
Duodenal contents, human |
4.8-8.2 |
Feces,
human |
4.6-8.4 |
Urine, human |
4.8-8.4 |
Milk, human |
6.6-7.6 |
Bile, human |
6.8-7.0 |
|
FOOD PRODUCTS |
Apples |
2.9-3.3 |
|
Olives |
3.6-3.8 |
Apricots |
3.6-4.0 |
|
Oranges |
3.0-4.0 |
Asparagus |
5.4-5.8 |
|
Oysters |
6.1-6.6 |
Bananas |
4.5-4.7 |
|
Peaches |
3.4-3.6 |
Beans |
5.0-6.0 |
|
Pears |
3.6-4.0 |
Beers |
4.0-5.0 |
|
Peas |
5.8-6.4 |
Blackberries |
4.9-5.5 |
|
Pickles, sour |
3.0-3.4 |
Bread, white |
5.0-6.0 |
|
Pickles, dill |
3.2-3.6 |
Beets |
4.9-5.5 |
|
Pimento |
4.6-5.2 |
Cabbage |
5.2-5.4 |
|
Plums |
2.8-3.0 |
Carrots |
4.9-5.3 |
|
Potatoes |
5.6-6.0 |
Cheese |
4.8-6.4 |
|
Pumpkin |
4.8-5.2 |
Cherries |
3.2-4.0 |
|
Raspberries |
3.2-3.6 |
Corn |
6.0-6.5 |
|
Rhubarb |
3.1-3.2 |
Crackers |
6.5-8.5 |
|
Salmon |
6.1-6.3 |
Dates |
6.5-8.5 |
|
Sauerkraut |
3.4-3.6 |
Eggs, fresh white |
7.6-8.0 |
|
Shrimp |
6.8-7.0 |
Flour, wheat |
5.5-6.5 |
|
Soft drinks |
2.0-4.0 |
Gooseberries |
2.8-3.0 |
|
Spinach |
5.1-5.7 |
Grapefruit |
3.0-3.3 |
|
Squash |
5.0-5.4 |
Grapes |
3.5-4.5 |
|
Strawberries |
3.0-3.5 |
Hominy (Iye) |
6.8-8.0 |
|
Sweet potatoes |
5.3-5.6 |
Jams, fruit |
3.5-4.0 |
|
Tomatoes |
4.0-4.4 |
Jellies, fruit |
2.8-3.4 |
|
Tuna |
5.9-6.1 |
Lemons |
2.2-2.4 |
|
Turnips |
5.2-5.6 |
Limes |
1.8-2.0 |
|
Vinegar |
2.4-3.4 |
Maple syrup |
6.5-7.0 |
|
Water, drinking |
6.5-8.0 |
Mild, cows |
6.3-6.6 |
|
Wines |
2.8-3.8 |
|
Source :
"Modern
pH and chlorine control"
by W.A. Taylor & Co.
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