Developing Metals Flashcards
a transition metal is…
a d-block element that can form at least one stable ion with an incomplete sub shell
variable oxidation state means…
an element that can have multiple oxidation states
what oxidation states can iron exist as?
Fe 2+ and Fe3+
what oxidation states can copper exist as?
Cu+ and Cu2+
transition metals form _____ ions in solution
coloured
Fe 2+ ions in solution are…
pale green
Fe 3+ ions in solution are…
yellow
Cu2+ ions in solution are…
blue
metals have giant _____ _____structures
metallic lattice
how are metallic bonds created?
the electrons in the outer shell are delocalised and free to move, leaving a positive metal ion. this ion is attracted to delocalised electrons and form a sea of closely packed positive ions in a sea of delocalised electrons
explain the order of filling of the 3d and 4s sub shell in terms of every level and spin pairing
The electrons fill up sub shells from the lowest energy level first. The 4S sub shell has a lower energy level than the 3D sub shell, which means it fills up first
write the electron configuration for Fe2+
1s2 2s2 2p6 3s2 3p6 3d6
write the electron configuration for Cu2+
1s2 2s2 2p6 3s2 3p6 3d9
copper prefers to have a ___ 3d sub shell and just ___ electron in the ___ sub shell
full
one
4s
write a method to determine the concentration of Fe2+ ions in a solution of iron chloride by titration
- put 25cm3 of iron chloride in conical flasks using pipette
- fill burette with standard solution of KMnO4
- add KMnO4 until permanent colour change to pink
- Record volume added
- Repeat for concordant results
why is zinc not classified as a transition metal?
there are no zinc ions with an incomplete sub shell
what properties does a transition metal have?
•the existence of more than one oxidation state in its compounds
•the formation of coloured ions
a heterogenous catalyst is…
A catalyst that is in a different state to the reactants
a homogenous catalyst is…
A catalyst that is in the same state as the reactants
why are transition metals good catalysts?
they have multiple oxidation states so can easily gain an electron and then give it back or can easily lose an electron and gain it back
a ligand is…
a molecule or ion with an available lone pair of electrons to form a covalent bond
a complex ion is…
a transition metal ion surrounded by one or more ligands
a d-orbital is…
a space where you could find a pair of electrons in a D sub shell
Explain why transition metals in solution are coloured
ligands split the d-orbitals into slightly different energy levels, creating a small gap between energy levels. E=hv so this gap creates a wavelength in the visible range. visible frequencies absorbed and complimentary colours are transmitted
why are transition metal ions coloured when hydrated?
water off crystallisation acts as ligand causing d orbitals to split and cause a gap in energy levels in the visible range so complementary colour transmitted
why are transition metal ions not coloured when anhydrous?
anhydrous don’t have ligands so energy gap between levels is too large and out of the viable range so no cloud seen
explain why group 1 and 2 metals are not coloured
don’t have partially filled d sub shells so electrons can’t be promoted from one d orbital to another causing a split. Therefore the energy gap is too large and out of the visible range so not coloured
give the ionic equation for when Fe2+ reacts with NaOH solution
Fe2+ + 2OH- —> Fe(OH)2
what is observed when Fe2+ ions react with NaOH
green gelatinous precipitate
give the ionic equation for when Fe3+ reacts with NaOH solution
Fe3+ + 3OH- —> Fe (OH)3