Properties of acids
Acids are complex chemical substances which contain hydrogen atoms that can be substituted by the atom of metal to form a salt.
Acids differ in basicity: Basicity is determined by the number of hydrogen atoms included in their composition. For example, sulphur - H2SO4 - dibasic, because it is composed of 2 hydrogen atoms.
Acid also share on oxygen-containing and not containing oxygen. For example, HCl - does not contain atoms of oxygen, and H2CO3 - carbonic acid contains 3 atoms of oxygen and is oxygenated.
Now let consider the properties of acids and their chemical reaction with simple and complex substances.
Main chemical properties of acids:
- reaction with metals:
H2SO4 +Zn → ZnSO4 + H2 - salt and hydrogen are Formed
V arious products of chemical reactions are obtained depending on the concentration of the acid.
For example, 2H2SO4 + Cu → CuSO4 + SO2 +2H2O in this case, the sulfuric acid is concentrated. Not concentrated acid doesn't react with copper (Cu).
- reaction with basic oxides and amphoteric oxides:
CuO + H2SO4 → CuSO4 + H2O ;
SnO + HCl → SnCl2 + H2O (tin oxide - tin oxide is an amphoteric oxide)
- reaction with bases and alkalis:
HCl + KOH → KCl + H2O this reaction is also called the reaction of neutralization - salt and water are formed;
Cu(OH)2 + 2HCl → CuCl2 + 2H2O
- reaction with salts:
The chemical reactions of acids with salts must consider the main signs of chemical reactions, namely, a chemical reaction will take place, if gas exuded, sediment fall out, and so on
N2CO3 + 2HCl → 2NaCl + CO2 + H2O - carbon dioxide CO2. Of course, strictly speaking, forms a weak carbonic acid (H2CO3), which immediately breaks down into carbon dioxide and water. This reactions forms salt and other acid (less weak).
Now consider the main methodsgetting acids
Getting acids is produced by the following chemical reactions:
reaction acid oxides with water:
SO3 + H2O → H2SO4;
CO2 + H2O → H2CO3;
- reaction with salts:
NaCl + H2SO4(conc.) → HCl + Na2SO4 - this chemical reaction forms a new acid weaker than sulfur, but too strong and other salt;
- reaction of non-metals with hydrogen and dissolving them in water:
H2 + Cl2 → HCl (we must remember that this chemical compound is hydrogen chloride - gas HCl acid is not acid. If you want to receiv it you can the gas HCl dissolve in water). Similarly comes with gas hydrogen sulfide:
H2 + S → H2S;
- the oxidation of some common substances:
P + 5HNO3 +2H2O → 3H3PO4 + 5 ? NO (in this chemical reaction is the oxidation of phosphorus (P) by nitric acid (HNO3) and phosphoric acid is formed (H3PO4) with the nitric oxide (NO)
Potassium permanganate. Peroxide
Interesting chemistry. Interesting experiments
Getting acid at home. The acidity of the water