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.