Transition metal chemistry Flashcards
topic 3
Transition metals
- hard, high melting solids
- conduct heat and electricity
- readily lose electrons to form stable cations
- variety of oxidation states available to most
- form a wide range of coordination compounds with different ligands and molecular geometrics centre on metal ions
- many are highly coloured and/or paramagnetic
Aufbau principle
electrons are added to the lowest energy orbital first
Hund’s rule
electrons fill empty orbitals before pairing and the unpaired electrons adopt the same spin values
Pauli exclusion principle
no two electrons may have the same set of quantum numbers (n, l, mI, ms)
groups 3 to 7 redox
highest oxidation state corresponds to group number
platinum metals - important in catalysis
- Ruthenium
- Osmium
- Iridium
- Palladium
- Platinum
- Rhodium
Form stable cations in water
d block ions
lost s electrons before d electrons
Mn2+ and Fe3+ are d5 ions
lower oxidation states what compound type
ionic
higher oxidation states what compound type
covalent
f-block/group 3/elements of the first transition series (not Cu) react with aqueous solution of acids to give what?
hydrogen gas and solutions of corresponding salts
Transition metals and halogens form?
anhydrous halides
anhydrous halides reaction from halogen and metal
2Fe + 3Cl2 –> 2FeCl3 iron (III) chloride
anhydrous halide reaction from metal halide and additional metal
Fe + 2FeCl3 –> 3FeCl2 iron (II) chloride
gives metal halide of lower oxidation state
Ox state of product of F + transition metal
highest possible
synthesis of aqueous sol of halides
react with salts of hydrohalic acids
NiCo3 + 2HF –> NiF2(aq) + H2O + CO2
nickel (II) fluoride
Co(OH)2 + 2HBr –> CoBr2(aq) + 2H2O
cobalt (II) bromide
Transition metal + acid
dissolves to halide salt and hydrogen gas
Mn + 2HCl –> MnCl2 +H2
Electronegativity and ox states
transition metals halides with low ox. states are more ionic
heavy d-block elements have significant covalent character
.
oxides and ox. state
low ox = ionic
high ox = covalent
Oxides and ph
low ox = basic
high ox = acids
Soluble hydroxide + aq sol of transition metal
gelatinous precipitate
sometimes the precipitate is a hydrated oxide (composed of metal ion, oxide ions and water of hydration)