Oxides Flashcards
What is the effect of moving across the period on the oxide given?
The oxides change from very high melting point solids to low melting point solids, liquids or gases
What do the ionic lattices of sodium and lithium consist of?
Discrete positive metal ions and negative oxide ions
What do the low melting point and boiling point compounds of the non-metals (CO2, P4O10) consist of?
Discrete covalent molecules
What do the high melting point solids of group 2 and 3 (BeO, MgO and Al2O3) consist of?
Giant structures of positive metal ions, and negative oxide ions which confer particular stability.
What is magnesium oxide used to make?
High melting point, chemically inert linings for furnaces and ladles.
Why is Silicon Dioxide an exception?
It has a high melting point because of the covalent lattice. When this structure is disrupted with metal ions, glasses are produced.
What does the type of glass depend on?
The metal
What is the conductivity of ionic oxides?
High
What is the conductivity for covalent oxides?
Zero
What is the conductivity of the intermediate metalloid oxides
Because of the sufficient covalent character electrical conduction is prevented
What is the pH of an Ionic oxides when it is dissolved in water?
Basic
What is the pH of non-metal oxides when dissolved in water?
Acidic
Why can silicon dioxide be considered an acidic oxide?
Because it will dissolve in alkali to form the silicate ion.
What are Amphoteric oxides?
Oxides that exhibit both acidic and basic properties.
What is the formula of Sodium aluminate?
Na3Al(OH)4
