Group 4 - Unit3.3 Flashcards
what causes significant changes in the chemistry of group 4 elements
elements at top = nonmetals
elements at bottom = metallic
carbon vs lead
CARBON:
- nonmetal
- form covalent compounds
- stable +4 OS
(acidic oxides)
carbon vs lead
LEAD:
- metal
- form ionic compounds
- stable +2 OS
(amphoteric oxides, never completely lose acidic character)
how do oxidation states change down the group(4)
due to increasing significance of inert pair effect, stability of lower oxidation states increase down the group.
most stable oxidation state of Carbon:
+4
most stable oxidation state of Silicon
+4
most stable oxidation state of Germanium
+4
most stable oxidation state of Tin
+4
most stable oxidation state of Lead
+2
what governs redox properties
stability of oxidation states
what is the stablest form of carbon
CO2
why is CO a reducing agent
easily oxidised from +2 to +4
is tin a reducing agent
yes
what is the most stable form of lead
PbO
why are all lead(2) compounds oxidising agents
easily reduced
from +4 to +2
very strong oxidising agent:
PbO₂
what are tetrachlorides
stable chlorides of carbon(CCl₄) and silicon(SiCl₄)
what shape are group 4 chlorides
tetrahedral
why is there no reaction between CCl₄ and water
massive amounts of energy are needed to break CCl₄ bonds.
why is there a reaction between SiCl₄ and water
reacts very quickly in hydrolysis
3d orbitals can accept the lone pairs from H2O to form coordinate bonds.
what is the overall equation for SiCl₄ and water
SiCl₄ + 2H₂O –> SiO₂ + 4HCl
what do group 4 chlorides look like
white solid
what is the most stable form of Pb
Lead Chloride
what type of compound is lead chloride
ionic compound
does lead chloride react with water
no
is lead chloride soluble in water
insoluble
are lead(ii) compounds soluble in cold water
all insoluble except Pb(NO₃)₂
what does Pb²⁺ and OH⁻ form
white precipitate
what does Pb²⁺ and excess OH⁻ form
white precipitate redissolves
what does Pb²⁺ and Cl⁻ form
dense white precipitate
what does Pb²⁺ and I⁻ form
bright yellow precipitate
