group 14 Flashcards
(25 cards)
What is the group oxidation state for group 14?
+4, also form +2
When is carbon in a +2 state?
reaction intermediates, carbenes
When is silicon in a +2 state?
Only stable at high temperatures, dihalides
Which elements of group 14 are well established at +2 oxidation state?
Germanium and Tin
What are the three allotropes of carbon?
Diamond, graphite, fullerenes
Describe the bonding of carbon in diamond
Diamond has an infinite three-dimensional network system containing interconnected tetrahedral carbon atoms.
The bonding in diamond is covalent.
Describe the structure of carbon in graphite
Planar hexagonal rings that fuse to form sheets.
Why is the hybridization of carbon in graphite important to its properties?
The carbons are sp2 hybridized, the electron in the pz orbital is delocalised making it good electrode material.
How are the sheets of graphite held together?
LDFs
Describe the structure of carbon in fullerenes
It consists of a nearly spherical C60 molecule, built from hexagons and pentagons of carbon atoms and with the shape of a football.
What coordination is silicon mostly?
4
How does silicon generally exist?
SiO2 (silicate) & [SiO4]4-
Which group 14 element is least common?
Germanium
How does Ge exist in the environment?
In some silver and zinc ores.
What is the most common form of Tin?
Casserite SnO2
How can metallic tin be obtained from Casserite?
By reduction
Which of the group 14 elements dissolve in most acids?
Tin and Lead
Which elements is group 14 are only attacked by HF?
Si & Ge
Which group does all of group 14 react with?
17 - halogens
What is an orthosilicate?
isolated tetrahedral
What is a pyrosilicate?
Two tetrahedra together
What is a ring silicate?
Cyclic structure
What is a chain silicate?
Pyroxenes
What is a double chain silicate?
Amphiboles
