ch 24 transition metals Flashcards
define a transition mental with its other names and its excetions
d-block elements: are d block elements that can form at least one stable ion with an incomplete d-subshell, hence sc(its stable ion is 3+) and zn (its stable ion is 2+) wich still has full d-subshell
Remeber 4s electrons are lost prior to 3d
4 general properties of transition metals
- ductile- ability to be drawn into wire
- good cinductor
- high mp/bp
- malleable - hammered pressed without breaking
- (shiny, giant metalic structure, high density)
4 unique properties of transition metals
- form compounds with differnt oxidation states
- form coloured compounds
- they act as cataltys
define catalyst and its two types and why TM are well suited
catalys: substances that increase the rate of a chmeicla reaction without being used up itself changing by providig alternative reaction pathway with lower activation energy
heterogenous
reractant and catalyst are differnt physical state.
provide a site for the reaction reactant is adsorbed onto surface and then products are desorbed, lowering the Ea
homogenous
reactant and catalyst are in the same physical state.
TM: variable oxidation states mean that it can loose and gain e- easily and form part of an intermediate this transfer of e- can speed up reactions
Harber process
* use
* equation
* catalyst
* homo or hetero
Iron
fertiliser
N2+3H2 <-> 2NH3
hetero
Contact process
* use
* equation
* catalyst
* homo or hetero
catalyst V2O2
hetero
2SO2 + O2 <->2SO3]
use: production of sulfur trioxide
Hydrogenation of alkenes
* use
* equation
* catalyst
* homo or hetero
use margarine
catalyst Ni
hetero
decompostition of hydrogen peroxide
- use
- equation
- catalyst
- homo or hetero
MnO2
H2O2 <->H2O + O2
hetero
Harber process
* use
* equation
* catalyst
* homo or hetero
Homo
Fe2+
a) S2O3 2- + Fe 2+ -> SO4 2- + Fe 3+
b) Fe3+
a ligand
a molecule or ion
that can donate a pair of
electrons with the transition
metal ion to form a coordinate
bond.
The coordination number is
The coordination number is
the total number of coordinate
bonds formed between a
central metal ions and its
ligands.
a complex ion is
a transition
metal ion bonded to one or
more ligands by coordinate
bonds.
A complex ion is a central transition metal ion
surrounded by ligands.
The transition metal ion accepts the pair of electrons from the
ligand in forming the coordinate (dative covalent) bond.
the ligands we need to learn and there charges
- Water
:OH2
no charge - Ammonia
:NH3
no charge - Thiocyanate
:-SCN
-1 - Cyanide
:-CN
-1 - Chloride
:Cl-
-1
Hydroxide
:-OH
-1
3 bidentate ligands we need to learn:
- Ethane-1,2-diamine, H2NCH2CH2NH2
- The ethandioate ligand C2O42-. Each O- in the ion can form a
coordinate bond with a transition metal ion.
four complex ion shapes and when they form
linear 180
tetrahedral - 109.5 often larger ligands such as cl
square planar - 90 transition metals with 8 d-electrons in the highest energy sub shell platinum (II) palladium (II) Gold (II)
octaheral small ligands like oc cn nh3
co-ordinate bond and dative covalent bond def
both electrons come from the same atom
what are the two types of stereoisomerism expressed by complex ions
cis-trans
optical
cis and trans isomerism
if the same ligands are opposite 180 away from another its trans if theyre within 90 of one anothe its cis
optical isomerism
enantimores are non superimposable mirror images
cis platin
cis is the only isomer with functional activity
its a cancer treatment drug, prevents the cancerous cells dividing by binding to dna side effects other cells are also damaged such as kidney and it can supresss the imune system
V2+
violet
VO3+
yellow
Mn 2+
pink
Cr 2+
blue
V3+
green
Cr3+
green
VO2+
blue
MnO4-
Purple
Cr2O7 2-
orange
VO2 +
yellow
Cu2+
blue
Fe 2+
green
vandium neumonic
V +5 Y
V+4 B
V+3 G
V+2 V
you better get vandium
ligand subsitution of copper
[Cu(OH2)6]2+ + 4Cl- reversible [Cu(Cl)4]2- + 6H2O
pale blue to yellow
(from excess hcl)
green intermediate as the wtw mix
