Topic 4 Flashcards
Why do copper and chromium not follow the aufbau principle?
This is because half filled and completely filled sub shells are very stable and preferred energetically.
What are common oxidation states?
Oxygen = -2
Hydrogen = +1
Halogens = -1
Alkali metals = +1
What does an increase in oxidation state mean?
It shows that oxidation has occurred
What does a decrease in oxidation state mean?
It means that reduction has occurred
What has happened to a substance if it is acting as a reducing agent?
It has been oxidised
What has happened to a substance if it is acting as an oxidising agent?
It has been reduced
What are the common ligands?
Water, cyanide(negative charge), ammonia, hydroxide ions(negative charge), halide ions(negative charge), oxalate ions(2 negative charge)(bidentate)
What is the coordination number?
The total number of bonds from the ligands to the central transition metal
What are the names of ligand complexes?
Halogens - end with -ido Cyanide - cyanido Ammonia - ammine Water - aqua Oxalate - oxalato Hydroxide - hydroxido Oxide - oxo
What are the names of the transition metal complexes?
Vanadium - vanadate Chromium - chromate Manganese - manganate Iron - ferrate Cobalt - cobaltate Nickel - nickelate Copper - cuprate Tin - stannate Lead - plumbate
How is complex formulae written?
Symbol of metal comes first, followed by ligands. Ligands should be written alphabetically, by symbol. Square brackets surround the metal complex.
What is d orbital splitting?
The non bonding pair of electrons supplied by the ligand causes the electrons in the d orbitals to be repelled. This increases the energy of some of the d orbitals, causing them to split and no longer be degenerate.
How do coloured complexes work?
If the wavelength absorbed is in the visible region, the colour corresponding to that wavelength is removed from the colour spectra, and the complementary colour is observed.
Why do some complexes appear colourless?
Some electrons can be promoted to higher energy levels when energy corresponding to the ultraviolet region of the electromagnetic spectrum is absorbed. These complexes appear colourless. The colour of the complex also depends on the number of d electrons present in the metal ion.
How do heterogeneous transition metal catalysts work?
They work by using unfilled/partially filled d-orbitals to bind to the reactants
