TRANSITION METAL CHEM Flashcards
to oxidise a tm to a higher oxidation state what must you add
an alkali followed by an oxidising agent
how woukd you stabilise a tm with a low oxidation state such as fe2+
place in acidic conditions
define a tm
a partially filled d orbital
what are some chemical properties of a tm
variable oxidation states
partially filled d orbitals
form colourful compounds
can form complex ions
they are good catalysts
what is a ligand
will donate a pair of electrons around the central metal ion to form coordinate bonds
what is a monodentate ligand
has only one coordinate bond around the central metal ion
what is the coordination number of a complex ion
how many coordinate bonds the ion has
can a bidentate ligand form optical isomers
yes
define a bidentate ligand
donates two electron pairs to a tm from different atoms on the same molecule
define entropy
amount of disorder in a system
what happens when you add EDTA to a solution of TM salts
the EDTA will replace all six water ligands in the hexa-aqua ion
how can a more stable complex form
increase entropy
describe what a cis molecule looks like
same side
describe what a trans molecule looks like
across from one another
which is larger ammonium ion or chloride ion
chloride - this will affect shape - and effect hoe many ions can fit around the central metal ion
are scandium and zinc tms
no - because they do not have partially filled d orbitals - they are full when they form stable ions
sc3+ has the configuration as Ar
Zn2+ - Ar 3d10 4s2
what are some physical properties of a tm
high density
high melting and boiling points
what type of isomerism is optical isomerism
stereoisomerism
define stereoisomerism
same molecular formula but different orientation of their bonds in space
how does colour arise in a tm
electronic transition from the ground state to the excited state. visible light is absorbed to promote these d-electrons to go to higher states. the light that is not absorbed is transmitted through a solution or reflected in a solid to give colour
what is the equation for the speed of light
speed of light = wavelength x frequency
c=lamda x f
what does the frequency of light absorbed depend upon
the energy difference between levels
what effects energy in an ion complex
the oxidation state of the central metal ion
ligands - shape -
- coordination number
do ligands intensify colour
yes
how do you dimerise a complex
add acid
how do you monomerise a complex
add an alkali
when oxidising low oxidation states why is an alkali added
there is a greater tendency to form negative ions
OH-
explain the steps of colourimetry
make a metal ion solution of known concentrations
of decreasing concentrations - dilution series
- measure the percentage absorption in the colourimeter
- measure the unknown concentration’s percentage absorption
- plot a calibration curve
- interpolate the graph to find the unknown conc
what si the colour of aq Fe2+
green solution
what is the colour of NaOH with (Fe(h2O)6)2+
green ppt
Fe(H2O)4(OH)2
what is the colour of excess NaOH and the Fe2+ hexaaqua ion
green ppt
Fe(H2O)4(OH)2
what is the colour of FE2+ with NH3
Fe(H2O)4(OH)2
GREEN PPT
what is the colout of Fe2+ with excess NH3
green ppt
Fe(H2O)4(OH)2
what is the colour of the Cu2+ as an aqueous ion
blue solution
(Cu(H2O)6)2+
what is the colour of Cu2+ hexa aqua ion with NaOH
blue ppt
Cu(h2O)4(OH)2
what is the colour of CU2+ with excess NaOH
blue ppt
Cu(H2O)4(OH)2
what is the colour of Cu2+ NH3
Cu(H2O)4(OH)2
blue ppt
what is colour Cu2+ excess NH3
deep blue solution
Cu(H2O)2(NH3)4)2+
what is the colour of Fe2+ with Na2CO3
FeCO3 SOLID
green precipitate
what is the colour of Cu2+ with NaCO3
Blue ppt
CuCO3
what is the colour of aq Fe3+ as a hexaaquaion
purple solution
Fe3+ with NaOH
Fe(h2O)3(OH)3 BROWN PPT
Fe3+ with excess NaOH
Fe(H2O)3(OH)3
brown ppt
fe3+ with NH3
Fe(H2O)3(OH)3 BROWN PPT
Fe3+ with excess NH3
fe(h2o)3(oh)3 brown ppt
Fe3+ with Na2CO3
CO2 is evolved
Fe(h2o)3(oh)3 brown ppt
23233
what is the colour of Al 3+ in aqueous solution
Al(h2o)6)3+
colourless solution
Al3+ with NaOH
Al(H2O)3(OH)3
white ppt
Al3+ with excess NaOH
Al(OH)4)-
colourless solution
Al3+ with NH3
Al(H2O)3(OH)3
white ppt
Al3+ with excess NH3
Al(H2O)3(OH)3 white ppt
Al3+ Na2CO3
Al(H2O)3(OH)3
white ppt
and CO2 gas evolved
23233
what is the colour of VO4 3-
yellow
what is the colour of VO2+
blue
what is the colour of V3+
green
what is the colour of V2+
violet
what si the oxidation state of VO4 3-
5
what is special about Al(h2o)3(oh)3
amphoteric
it can act as an acid or a base
and can be dissolved in either
what is the ligand substitution between Cu(h2o)6)2+ and 4Cl-
Cu(Cl4)2- + 6H2O
THE COMPLEXES GO FROM BLUE YELLOW
what is the equation for the ligand substitution Co(H2O)6)2+ and 2NH3
Co(h2o)4(oh)2) + 2NH4+
IT IS A REVERSIBLE REACTION.
is there a stronger bond between N AND Cu or Cu and O
Cu and N