How do the acidic and basic characters of oxides of the s and p block elements change on moving across a period and down the group?
Answers
Explanation:
From left to right on the periodic table, acid-base character of oxides and hydroxides go from basic to acidic.
Increasing charge on an anion increases the production of basic solutions.
As electronegativity increase, production of ionic cations increases because elements are more able to adopt a cation.
As ionization energy increases, the acidic nature increases.
Metallic Oxides:
- Ionic Bonding: no distribution of electron wave function
- Ionic oxides are usually basic (element act as a base when reacting with H2O)
Na2O(s) + H2O(l) --> 2NaOH(aq) --> 2Na+(aq) + 2OH-(aq)
B. Oxide B. Hydroxide
Semimetal Oxides:
- Semimetal are amphoteric (elements acts as an acid and/or base when reacting depending on pH of solution)
Al2O3 --> Al(OH)3 --(3H+)--> [Al(H2O)6]^(3+) (aq)
--(OH-)--> [Al(OH)4]-(aq)
Non-Metal Oxides
- Covalent Bonding: almost complete distribution of electron wave function
- Covalent oxides are usually acidic (elements act as an acid when reacts with H2O)
SO3 + H2O(l) -> H2SO4(aq) -> H+ + HSO4-
A. Oxide A Hydroxide
Ionic Hydrides
0 6 a
Types of Hydrides
- Ionic Bonding: no distribution of electron wave function
- Bronsted Basic because they will react with proton
- Lewis Basic because they can be ligands
CaH2 + 2H2O -> 2H2 + Ca(OH)2
H- H+ H2
-In this case, CaH2 is basic because it reacts with water (an acid in this case) to form many hydrides by reducing a proton.
Covalent Hydrides
- Covalent Bonding: almost complete distribution of electron wave function
HF + H2O -> F- + H3O+ ....can also be written as HF(aq) <--> H+(aq) + F-(aq)
H+ H+ H+
- HF is a weak acid that is bronsted acid because it will loose a proton. Therefore, HF is the weak acid, where the water acts as a silent water, and F- is the weak conjugate base.