Transition Metals Flashcards
What is the definition of a transition metal
An element which forms at least one stable ion with a partially filled d subshell
What is a complex
A central atom or ion with ligands bonded by coordinate bonds
What is a ligand
An ion or molecule with a lone pair of electrons which forms a coordinate bond with a central metal atom or ion in a complex
What is a coordination number
The number of coordinate bonds to a central metal atom or ion in a complex
What is a monodentate ligand
A ligand which uses only one lone pair of electrons to form a coordinate bond with a central metal atom or ion
What is a polydentate ligand
A ligand which uses many lone pairs of electrons to form more than two coordinate bonds with a central metal atom or ion in a complex
What is the definition of a bidentate ligand
A ligand which uses two lone pairs of electrons to form two coordinate bonds with a central metal atom or ion in a complex
What are the properties of transition metals
Hard High mp High density Form complexes Form coloured aqua Compounds with varying oxidation states Metal + ion acts as catalyst
Describe the increase in IE across transition series
- 3d lower in energy than 4s
- transition metal formed by addition of electron to inner 3d
- electron added to inner shell means better shielding of outer 4s electrons from the increased positive nuclear charge
- atomic radius shows only a small decrease
What is the general formula of a complex
See notes
What is the charge of the complex if the ligand is neutral
The charge = the O.N of the metal
What is the charge if the ligand is anionic
ON of metal + (no. Of ligands x charge of ligand)
What does the chelate effect mean
Increase in entropy means replacement will happen
What is the order of stability in ligands
H2O < Cl4 < NH3 < en < edta
Name the four ions that are green
Cr^3+
V^3+
Fe^2+
Ni^2+
What are the two yellow metal ions
Chromate (VI) ➡️ CrO4^2-
V(V) ➡️ VO2^+
What are the two pink metal ions
Mn^2+
Co^2+
What are the two blue metal ions
Cu^2+
V(IV) (VO^2+)
What is the violet metal ion
V^2+
What are the two orange metal ions
Dichromate (VI) ➡️ Cr2O7^2+
Fe^3+
What is the colour change when zinc reduces ammonium vanadate (V) in conc HCl
Yellow ➡️ blue ➡️ green ➡️ violet
Draw the structure of edta
See notes
Draw the structure of en
See notes
Describe the strength of the en ligand
Two N containing lone pairs Alkyl group pushes e away Small amount of extra negative charge on N Makes lone pair more available Stronger ligand
Describe the strength of the phenylamine ligand
Weaker in strength
Lack of intense charge around N
Need to break some delocalisation
What colour is the precipitate of (Cr(H2O)6)^3+ and what colour is it in NaOH and NH3
Blue green
Green (Cr(OH)6)^3- (aq)
Not soluble so stays same as start
What colour is the precipitate of (Mn(H2O)6)^2+ and what colour is it in NaOH and NH3
White which darkens to brown/black on standing
Not soluble
Not soluble
What colour is the precipitate of (Fe(H2O)6)^2+ and what colour is it in NaOH and NH3
Green
Not soluble
Not soluble
What colour is the precipitate of (Fe(H2O)6)^3+ and what colour is it in NaOH and NH3
Brown
Not soluble
Not soluble
What colour is the precipitate of (Co(H2O)6)^2+ and what colour is it in NaOH and NH3
Blue
Not soluble
Yellow (changes to brown on standing) (Co(NH3)6)^2+ (aq)
What colour is the precipitate of (Ni(H2O)6)^2+ and what colour is it in NaOH and NH3
Green
Not soluble
Blue (Ni(NH3)6)^2+ (aq)
What colour is the precipitate of (Cu(H2O)6)^2+ and what colour is it in NaOH and NH3
Blue
Soluble
Deep/dark blue (Cu(NH3)4(H2O)2)^2+ (aq)
