Transitional Metals Flashcards
What is a ligand?
A molecule or ion that forms a co-ordinate bond with a transitional metal by donating a pair of electrons
must have a lone pair
What is a complex ion?
central metal atom or ion surrounded by ligands
What’s significant about Cl- ion compared to NH3 and H2O
They have a large size
What are the 4 characteristics of transitional metal?
- complex formation
- formation of coloured ions
- variable oxidation state
- catalytic activity
Why Zn is not a transitional metal?
Zn2+ only forms so this means that there is complete d-orbitual hence not transitional metal
What is a bidentate ligand?
2 atoms with lone pairs and can form two coordinate bonds per ligand
Example of multidentate ligand
EDTA+
Explain the process of Haemoglobin and the effect of CO.
*Oxygen forms a co-ordinate bond to Fe(II) in haemoglobin
*This enables oxygen to be transported in the blood
—————
*CO is toxic because it forms a strong coordinate bond with haemoglobin and it replaces the oxygen
Equation to show formation of multidentate complexes from [Cu(H2O)6]2+
[Cu(H2O)6]2+ +EDTA4- —> [Cu(EDTA)]2- +6H2O
How do these metals present colour?
white light gets absorbed and electrons gets excited and only the colour lights gets reflected
Colours occur when the electron configuration has?
partially, filled d-orbitual
What kind of bonds are held in complex ion?
Dative Covalent bond
Charge of NH3, H2O
0
Octahedral has what kind of arrows and how many?
2 wedges, 2 dashes, 2 normal bond
What kind of transitional metals would be square planar? (sometimes)
Nickel, Platinum, Palladium
What kind of shape do Cl- tend be?
Tetrahedral (no matter what)
Cis and Trans means? use for inorganic
Cis (same)
trans (opposite)
In octahedral, if chlorine next to each other (90 degrees) then is it cis/trans
What makes it trans?
cis
if the chlorine is physically opposite to each other
Ions with higher oxidation state, absorb higher… ( but cant tell about a colour :( )
frequencies of light
3 ways in which a metal complex can be changed to alter its colour
ligand substitution
oxidation sate
coordination number
different ligands causes different…
d-orbitual splitting
what bidentate ligand is NH2-CH2-CH2-NH2? and what’s their charge
-en-
H2N-CH2-CH2-NH2
0 charge
What other examples of bidentate ligand
ethanedioate ( C with 2 double bond O and 2 bond with O- lone pair )
Why does a reaction proceeds in relations to chelate effect?
There are more particles on products than reactants
This increases entropy so it will be positive
As T always positive, Gibbs will be negative so reaction is feasible
what’s the charge of EDTA
4-
What is a heterogenous catalyst?
different phase from reactants
How to increase the number of active sites? Heterogenous only**
by increasing surface area,
a) making the catalyst: in ^powder
b) as a ^coating on a support medium
What is the 2 equations of the Contact process? Heterogeneous Catalyst
1) SO2 (g) + V2O5 (s) —-> SO3 (g) +V2O4 (s)
2) V2O4 (s) + 1/2 O2 (g) —> V2O5 (s)
How does the contact process lead to the creation of sulfuric acid?
SO3 (g) +H2O (l) —> H2SO3 (aq)
How does catalyst poisoning occur?
Impurities bind to a catalyst’s active sites and prevent it from functioning
How Fe2+ ions catalyse reaction between S2O8 2- and I-?
*Fe2+ ions and S2O8 2- ions attract as they have opposite charges
*Similarly with I-
*This means that activation energy decreases as before
*Iron’s variable oxidation state allows to react either reactants
What is the 2 equation of the contact process? Homogeneous catalyst
1) 1/2 S2O8 2- (aq) + Fe2+ (aq) –> SO4 2- (aq) +Fe3+ (aq)
2) Fe3+ (aq) +I- (aq) –> Fe2+ (aq) +1/2 I2 (aq)
Explain the process of autocatalyst graph?
- Initially, the reactants are same charge so repel hence the reaction is slow
- it produces Mn2+, the catalyst increases the rate of reaction
- As the reactants gets used up, the rate decreases
What is the equation of autocatalyst? + overall
1) 4Mn2+ + MnO4- +8H+ —> 5Mn3+ +4H2O
2) 2Mn3+ + C2O4 2- —> 2Mn2+ +2CO2
- 2MnO4- +16H+ +5C2O4 2- —> 2Mn2+ + 10CO2 + 8H2O
What are all the colours of these metal-aqua ions? Fe2+, Fe3+, Cu2+ and Al3+
+(H2O)6
Fe2+ green solution
Fe3+ yellow solution
Cu2+ blue solution
Al3+ colourless
Which one will be a stronger acid x 2+ or x 3+ and why?
3+. A higher charge so greater attraction of electron and have smaller radius. higher charge/size ratio
What equation is when Ethane-1,2-diamine reacts with [Co(H2O)6] 2+
[Co (H2O)6]2+ + 3NH2CH2CH2NH2 →
[Co(NH2CH2CH2NH2)3]2+ +6H2O
Why same charged ions are very slow at start?
→ no catalyst start
→ same charge, repels
→ activation energy is high
