Flashcards in Group 3 A2 Deck (13):
All the elements in Period 3 except ______ and _______ combine directly with oxygen to form oxides.
except chlorine and argon
Give the equation for sodium combining with oxygen
4Na(s) + O2(g) 2Na2O(s)
Give the equation for magnesium combining with oxygen
2Mg(s) + O2(g) 2MgO(s)
Give the equation for aluminium combining with oxygen
4Al(s) + 3O2(g) 2Al2O3(s)
Give the equation for silicon combining with oxygen
Si(s) + O2(g) SiO2(s)
Give the equation for phosphorous combining with oxygen
P4(s) + 5O2(g) P4O10(s)
Give the equation for sulfur combining with oxygen
S(s) + O2(g) SO2(g)
What is unique about the structure/bonding of Al2O3?
Mostly ionic, but with significant covalent character.
Na2O, Al2O3 and MgO are ____ oxides and hence have a ______ melting point.
Na2O, Al2O3 and MgO are ionic oxides and hence have a high melting point.
Why do MgO and Al2O3 have a higher melting point than Na2O?
The charges are higher, resulting in a stonger attraction between the ions. Also Al2O3's bonding contains a lot of covalent character.
Are ionic oxides acidic/basic? State the equation.
Basic: O2-(aq) + H2O(l) 2OH-(aq)
Are covalent oxides acidic/basic? State the equation.
Acidic: MO(s) + H2O(l) MO(OH)-(aq)+ H+(aq)