Solutions of acids, bases and minerals

Acids:

• It is a substance whose aqueous solutions contain a positive proton (H⁺ )

• It changes the blue litmus paper gets red.

Such as: sulfuric, hydrochloric, nitric and phosphoric acids.

Bases:

• It is a substance whose aqueous solutions contain negative hydroxide ion OH^-

• Bases react with acids to get salt and water.

• It changes the red litmus paper gets blue.

• They have a soapy feel.

Such as: sodium hydroxides and potassium hydroxides.

Minerals:

• It is a chemical compound resulted from the reaction of an acid with an alkali.

Such as: sodium chloride, magnesium chloride, calcium sulfate and potassium chloride.

Economic importance of some common acids

Acids in the human body

1- Stomach acids help in the digestion of proteins.

2- During physical exercises, lactic acid is produced in muscles.

Acids and food

1- Tomatoes, guava and oranges contain vitamin C (Ascorbic acid).

2- Green leaves of vegetables contain folic acid necessary for the growth of cells.

Acids in the house

1- People use diluted acid solutions to clean surfaces.

2- Diluted hydrochloric acid is used in detergents المنظفات الصناعية , polishing metal surfaces needed to be coated.

Acids in industry

Nitric and phosphoric acids are used in the making of fertilizers.

Sulfuric acid is used in the car batteries, fibers industry and in oil distillation.

البترول تكرير

E conomic importance of some common bases

Bases and health

Bases like magnesium hydroxide are used in the manufacture of anti-acidity stomach medicines الادوية المضادة لحموضة المعدة .

Bases in industry

• Calcium hydroxide is used in the civil works الأعمال المعمارية as in the preparation of the cement mixture,

• In water treatment and the reduction of soil acidity.

Economic importance of some common minerals

Minerals in the human body

• Composing bones and teeth like calcium and magnesium minerals.

• Formation of tissues like phosphorous minerals.

• Transfer of nerve impulses like sodium and potassium.

Minerals and food.

Sodium chloride (food salt) is used in salting and preserving food.

Minerals in industry

1- Calcium carbonates are used in glass and cement manufactures.

2- Potassium nitrates are used in the manufacture of explosives and fertilizers.

3- Silver nitrates are used in the manufacture of sensitive camera films.

Lesson 3 Exercise

1- Write one economical importance for each of the following:

a. Sulfuric acid. …………………………………………………………………..

b. Calcium hydroxide………………………………………..……………………

c. Calcium carbonates. ………………………………………..………………………

d. Magnesium hydroxide………………………………………….……………………

e. Sodium chloride…………………………………………………………..………….

f. Hydrochloric acid…………………………………………………………………

g. Enzymes in the human body……………………………………………………..

h. Silver nitrates ……………………………………………………..