You oxides basics are binary compounds (made up of just two chemical elements) that have the oxygen with NOX equal to -2 linked to a metal* with NOX equal to +1, +2 or +3 or even some semi-metals.
*NOTE: The metal must belong to the families of alkaline, alkaline earth, Boron or be some transition element.
The chemical elements that can have NOX +1, +2 or + 3 that do not form basic oxides are:
Zinc (Zn)
Chromium (Cr): NOX +3 only
Iron (Fe): NOX +3 only
Lead II (Pb): NOX +2 only
Aluminum (Al)
Tin (Sn)
Arsenic (As)
Beryllium (Be)
Antimony (Sb)
Manganese (Mn): NOX +3 only
Bismuth (Bi)
Nomenclature
THE naming rule applied to basic oxides is as follows:
Oxide + de + element name
NOTE: If the metal does not belong to the family of alkali, alkaline earth or Boron, we must indicate the NOX of the element by means of a Roman numeral at the end of the name.
See some examples:
Dog
This oxide has the element calcium, which belongs to the alkaline earth family. This indicates that we don't need to indicate NOX in the name. Thus, the name of this oxide is:
Calcium oxide
FeO
This oxide has the element iron, which does not belong to the alkaline, alkaline earth and boron families. Thus, we must indicate the oxidation number in the oxide name.
As there is no index (number) in the formula, this indicates that the iron charge has the same number as the oxygen charge (-2), but with the opposite sign. So your NOX is +2. Therefore, the name of this oxide is:
iron oxide II
Ag2O
This oxide has the element silver, which is a transition element, but, according to the IUPAC rule, it does not need to indicate its oxidation number in the name of the oxide. Thus, the name of this oxide is:
silver oxide
K2O
This oxide has the element potassium, which belongs to the alkali family, which prevents us from writing any Roman numerals in the name. Thus, the name of this oxide is:
potassium oxide
Au2O
This oxide has the element gold, which does not belong to the alkaline, alkaline earth and boron families. For this reason, we must indicate the oxidation number of this element in the oxide name.
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As we have the index 2 on the metal, which comes from the crossing of the oxygen charge, automatically the index 1 which is in front of the oxygen comes from the crossing of the metal. Therefore, your NOX is +1. Thus, the name of this oxide is:
gold oxide I
Ga2O3
This oxide has the element gallium, which belongs to the Boron family. This indicates that we should not write its oxidation number in the name. Thus, the name of this oxide is:
gallium oxide
Characteristics of basic oxides
Like the basic oxides have metals and oxygen in their constitution, are called ionic compounds, that is, they are formed by ionic bonds. As they present this type of chemical bond, they have the following characteristics:
They are solid at room temperature;
They have high melting and boiling points;
Only those with alkali and alkaline earth metals have good water solubility.
Property chemistry, that is, they can be transformed into other substances according to the reagent with which they are mixed. See two examples:
1st) Example: when are mixed with water, undergo chemical reaction and form an inorganic base, as described in the equation below:
MeO + H2O → MeOH
See the reaction between bismuth oxide III and water:
Bi2O3 + 3 H2O → 2 Bi (OH)3
O Bismuth (load +3) interacts with hydroxyl (load -1), forming bismuth hydroxide III [Bi(OH)3], which has the index 3 because of crossover loads. As we have 2 bismuths in the reagent, it is necessary to place coefficient 2 in the base (bismuth hydroxide) and coefficient 3 in the H2O to equalize the amount of hydrogens and oxygens in the reactants and product.
2) Example: When this type of oxide is mixed with an acid, undergoes a chemical reaction, forming an inorganic salt and water, as described in the equation below:
MeO + HX → MeX + H2O
See the reaction between the calcium oxide and hydrochloric acid:
CaO + 2 HCl → CaCl2 + H2O
O calcium (cation that has NOX +2) interacts with chlorine (anion that has NOX -1), forming the CaCl salt2 (index 2 results from the crossing of charges) and water. As we have two chlorines and two hydrogens in the product, it is necessary to place the coefficient 2 in the reagent's HCl.
By Me. Diogo Lopes Dias
Would you like to reference this text in a school or academic work? Look:
DAYS, Diogo Lopes. "What is basic oxide?"; Brazil School. Available in: https://brasilescola.uol.com.br/o-que-e/quimica/o-que-e-oxido-basico.htm. Accessed on June 28, 2021.
