chapter 24 Flashcards
what are the properties of the first row of d-block elements?
giant metallic lattices
high melting and boiling points
conduct electricity
insoluble
what are the special cases of d block elements when forming ions?
chromium and copper
only one electron in 4s orbital
half filled 3d and filled 3d are more stable than filled 4s
what happens when d block elements form ions?
4s orbital fills before 3d orbital
what is a transition element?
d block element that forms at least one ion with a partially filled d-orbital
what d block elements are not transition elements?
scandium and zinc
what are properties of transition elements?
form coloured compounds
elements and their compounds can act as catalysts e.g. heterogeneous catalyst in haber process
ions have different oxidation numbers to element
what is a complex ion?
formed when one or more molecules/negative ions bond to a central metal ion
what are ligands?
molecule/ion that donates a pair of electrons to a central metal ion yo form coordinate/dative covalent bond
what is the coordinate number?
indicates number of coordinate bonds attached to central metal ion
what is a monodentate ligand?
donates one pair of electrons to central metal atom
what is a bidentate ligand?
donates two pairs of electrons to central metal atom
forms two coordinate bonds
(number of ligands does not correspond to coordinate number)
what is the shape of a complex ion with 6 coordinate bonds?
octahedral (90 degrees)
what is the shape of a complex ion with 4 coordinate bonds?
tetrahedral (109.5 degrees)
square planar (90 degrees)
what is stereoisomerism?
same structural formulae but different arrangment of atoms in 3D space
what do you need for cis-trans isomerism?
square planar of octahedral shape
two different monodentate ligands
what do you need for optical isomerism?
octahedral complexes
two or more bidentate ligands
what are precipitate reactions?
2 aqueous solutions containing ions react to form an insoluble ionic solid
what happens when you add aqueous NaOH to Cu 2+ solution?
blue to blue
what happens when you add aqueous NaOH to Fe 2+ solution?
pale green to green
what happens when you add aqueous NaOH to Fe 3+ solution?
pale yellow to orange-brown
what happens when you add aqueous NaOH to Mn 2+ solution?
pale pink to light-brown
what happens when you add aqueous NaOH to Cr 3+?
violet to grey-green
what happens when you add excess aqueous NaOH to Cr 3+?
dark green
what is a ligand substitution reaction?
one ligand in a complex ion is replaced by another ligand
what happens when you add aqueous ammonia to Cu 2+ solution?
blue to blue
what happens when you add excess aqueous ammonia to Cu 2+ solution?
blue to deep blue
what happens when you add aqueous ammonia to Fe 2+ solution?
pale green to green
what happens when you add aqueous ammonia to Fe 3+ solution?
pale yellow to orange-brown
what happens when you add aqueous ammonia to Mn 2+ solution?
pale pink to light brown
what happens when you add aqueous ammonia to Cr 3+ solution?
violet to grey-green
what happens when you add excess aqueous ammonia to Cr 3+ solution?
grey-green to purple
what happens when you add excess HCl to Cu 2+ solution?
pale blue to yellown
what happens with ligand substitution and haemoglobin?
central metal ion in haem group is Fe 2+
carbon monoxide is toxic as when breathed in, ligand substitution occurs and oxygen in haemoglobin is replaced
what is the colour change of the oxidation of Fe 2+ to Fe 3+ with Mn?
purple to colourless
what is the colour change of the reduction of Fe 3+ to Fe 2+ with iodine?
orange-brown to pale green and brown
what is the colour change of the reduction of Cr2O7 2- to Cr 3+ with zinc?
orange to green
with excess zinc it is green to pale blue
what is the colour change of the oxidation of Cr 3+ to Cr2O7 2-?
green to yellow
what is the colour change of the reduction of Cu 2+ to Cu + with iodine?
pale blue to white precipitate and brown
what is the colour change of the disproportionation of Cu +?
Cu is being reduced and oxidised
produces brown solid in blue solution
