Transition metals Flashcards
Write the electronic config of a Cu atom
[Ar]3d104s1
write the electronic config of a Fe2+ ion
[Ar]3d6
write the electronic config of a Fe3+ ion
[Ar]3d5
give the definition of a transition metal
A transition metal is one which forms one or more ions with partially filled d orbitals. That
would exclude scandium which only forms 3+ ions with the 3d level empty, and zinc which
only forms 2+ ions with the 3d level full.
Explain why iron can form a 3+ ion whereas calcium only forms a 2+ ion
The third ionisation energy of calcium is much greater than the third ionisation energy of
iron. In the calcium case, the gain in lattice enthalpy or hydration enthalpy in forming the 3+ ion
isn’t enough to compensate for the higher ionisation energy. In the iron case, it is.
What is the general name given to groups such as water, ammonia or chloride ions which
surround the central metal ion?
ligands
What colours are the [Cu(H2O)6]
2+ and [Cu(NH3)4(H2O)2]
2+ ions
[Cu(H2O)6]2+ –>pale blue
[Cu(NH3)4(H2O)2]2+ –>very dark blue
Name the catalyst in the Haber Process for the manufacture of ammonia.
Iron
explain how complex ions can absorb certain frequencies of light
The water molecules increase the energy of all the d orbitals, but there is now an energy gap
within the d orbitals, with two of the orbitals having a higher energy than the other three. If light of
the right frequency (and therefore energy) falls on the ion, an electron from the lower energy
orbitals can be promoted into the space in the higher energy orbital.
why are Zn2+ ions colourless
Does not have a partially filled d sublevel- there is no space in higher orbitals to promote electrons into
write a general equation for the reaction of a metal hexaaquaion with ammonia
[M(H2O)6}2+ + 2(NH3)–>[M(H2O)5(OH)] + 2(NH4+)
write the equation, with excess ammonia
[M(H2O)6]+ 4(NH3) –> [M(H2O)2(NH3)4]2+ + 2H20
how does the reaction of 2+ complex ions with carbonate ions differ to the reaction with 3+ ions
With 3+ ions, you get the complex ion e.g. [M(H2O)3(OH)3] (remember 2:3:2:3:3). With 2+ ions, you get the metla carbonate e.g. MCO3
What is a Bronsted-Lowrey base?
A substance that accepts protons
What is a Lewis base?
A substance that is able to donate a lone pair
what is a multidente ligand
ligands with a number of atoms capable of donating an electron pair producing several coordiante bonds
what is entropy
a measure of disorder
what sign should deltaG have for the reaction to be feasible
deltaG must be negative
why are tetrahedral complexes formed with Cl- ions
because Cl- ions are so big, only 4 bonds can fit around the central ions e.g. 4 cl ions bond with a central Co atom
give an example of a linear complex
[Ag(NH3)2]+
give an equation summarising the energy absorbed by bond when an electron moves from its ground state
deltaE=hv (h=planks constant)
what factors will determine the colour of the ion complex
ligands
coordination number
oxidation state of metal
how can you measure the concentration of metal ion complexes
using a colourimeter
what is the catalyst used in the contact process for the manufacture of sulphuric acid
V2O5
what is the reaction that takes place during the contact process
So2+V2O5–>So3+V2O4
what are heterogeneous catalysts
catalysts that are in a different phase to the reactants
give an example of a good metal catalyst
Platinum
what is the catalyst used in the Habor process for the production of ammonia
Iron
why is a honeycomb structure of the catalyst often used
to maximise surface area- greater area=more likely for reactants to collide with the catalyst
what is the intermediate species produced during stage 1 of the reaction between I- and S2O82-
Fe3+
The Fe3+ ion is then reacted with the I- ion to form I2 and Fe2+
write the two half equations that when combined, give the overall equation for the reaction of C2O42- with MnO4-
MnO4- + 8H+ + 5e- –> Mn2+ + 4H2O
C2O42- –> 2CO2 + 2e-
