Transition Elements Flashcards
Fe 2+ with NaOH
Fe(OH)2
Pale green to dark green ppt
Fe 3+ with NaOH
Fe(OH)3
Pale yellow to brown ppt
Mn 2+ with NaOH
Mn(OH)2
Pink to pale brown ppt
Cu 2+ with NaOH
Cu(OH)2
Pale blue to blue ppt
Cr 3+ (aq) with excess NaOH (2 step)
Cr(OH)3
Cr(OH)6
Violet soloution to grey green ppt to dark green soloution
Cr3+ with excess NH3 (2 step)
Cr(OH)3
Cr(NH3)6
Violet soloution to grey green ppt to purple soloution
Cu2+ with excess NH3 (2 step)
Cu(OH)2
Cu(NH3)4(H2O)2
Pale blue soloution to blue ppt to dark blue soloution
Cu2+ with Cl ions
Cu(Cl)4
Pale blue soloution to yellow soloution
(Mixture is green)
Cr2+
Pale blue
KCr(SO4)2 dissolved in water
Cr(H20)6
Violet
What is a dblock element?
Highest energy electrons In d orbitals
List some properties of transition metals?
Metallic, high mp and no , shiny ,conductive
How and why do chromium and coppers electron configuration differ to other transition metals?
They don’t pair in the 4s orbital as having a half filled d5 sub shell or filled d10 sub shell increases the stability of the atoms
When is the 4s orbital filled and empties in d-block ions
Filled first, emptied first
Definition for transition metals
D block elements that form at least one ion with a partially filled d subshell
Why are Scandium and zinc not classified as transition metals
The only ions they form don’t have partially filled d sub shell
- Sc^3+
- Zn^2+
List 3 properties of transition metal compounds
- Form compounds in which transition metal has different oxidation states
- coloured compounds
- act as catalysts
What oxidation number can all the transition elements have ?
2+
What colour is K2Cr2O7
Orange
Give 3 examples of Transition metals acting as catalysts in industry?
- Iron in the Haber process (ammonia production)
- V2O5 in the contact process (SO3 production)
- Nickel in hydrogenation of vegetable fat for margarine
What is a heterogeneous catalyst
Catalyst in a different state to reactants
What is a homogeneous catalyst
Catalyst in the same state as the reactants
What is a complex ion
One or more ligands bonded with dative covalent bonds to a central metal ion
What is a ligand
A molecule or ion that donates a pair of electrons to a central metal ion to form a dative covalent bond/ coordinate bond
What is coordination number
Number of coordinate bonds attached to central metal ion
What is a monodente ligand
Ligand that donates one pair of e to a central metal ion
3 Examples of monodente ligands?
Eg: H2O: , :NH3 , :Cl- , :CN- , :OH-
What is a Bixente ligand?
Donate two lone pairs of e to central metal ion
What are the two common bidente ligands
1,2-diaminoethane (shortened to en) Ethanediote ion (COO)2
What is the shape and bond angle of a complex ion with coordination number 6?
Octahedral , 90*
What is the shape and bond angle of most complex ions with four coordinate bonds?
Tetrahedral 109.5*
Give two examples of a tetrahedral ion
CoCl4 , CuCl4 (both have 2 minus charge)
What is the shape and bond angle for a complex ion with 4 coordinate bonds that nit tetrahedral ?
Square planar , 90*
When do square planar complexes occur , give an example
Transition metals ions with eight electrons in highest energy d sub shell so pd,Pt, Au
Eg [Pt(NH3)4]^2+
What colour is [Cu(H20)6]^2+
Pale blue
What does Cu^2+(aq) + NH3 make?
Cu(OH)2(s)
Pale blue to pale blue ppt
What happens when Cu^2+ is reduced by I- ions?
White ppt of CuI
Brown I2
What happens in disproportionation of Cu^+
Brown Cu solid and blue soloution of CuSO4
What colour is [Cr(H20)6]^3+
Violet
What happens when Cr^3+ aqueous reacts w NH3
Cr(OH)3(s)
Violet to Grey green ppt
What happens when Cr^3+ reacts w hot H2O2
Forms CrO4^2-
Yellow
What colour is [Mn(H2O)6]^2+
Pale pink
What colour is [Fe(H20)6]^2+
Pale green
What’s the colour change when MnO4^2- goes to Mn^2+
Purple to pale pink but so dilute it’s colourless
What happens when I-/Fe^3+ goes to I2/Fe^2+
Orange brown to brown
What colour is [Fe(H20)6]^3+
Yellow
