Transitition metals

Question 1

WWhat is a common characteristic for transition metals?

Answer 1

= incomplete d subshell

Question 2

What characterictsics are assocciated?

Answer 2

= complex formation
= coloired ion formation]
= variable oxidation states
= catalytic acitivty

Question 3

Why is zn not a trasitin metal?

Answer 3

= 2+ ion can only be formed, complete d orbital

Question 4

What is a complex ion?

Answer 4

= central metal ion surrounded by ligands bonded by dative covalent bond,

Question 5

What is a ligand?

Answer 5

= an atom, ion, or molecule which can donate an electron pair
= can be monodentate, biodentate and polydenate

Question 6

What are minodentate ligands?

Answer 6

= only one lone pair of electrons
= H2O:
= :Nh3
= :Cl-

Question 7

What are bidentate ligands?

Answer 7

= two lone pair of electrons
= ethanedioate
= ethane-1-2-diamine

Question 8

What are multidentate?

Answer 8

= ligands that have more than 1 dative covalent bond
= EDTA4+
6 coordinate bonds with the metal ion

Question 9

What is the shape of complex ions dependant on?

Answer 9

= size of ligands and coordination number- how many dative covalent bonds are formed around it NOT the number of ligands

Question 10

What do complexes with a coordiation number of 6 form?

Answer 10

= octahedral
= bonds are 90 degrees
=

Question 11

what do complexes with a coordination number of 4 form?

Answer 11

= tetrahedral
= square planar
= 109;5 degrees
= aquare complex is 90 degrees

= cis platin

Question 12

What do complexes with 2 coordination number form?

Answer 12

= linear shape
= specific example:
= [Ag(Nh3)2}+
= tollents reagant
= 180 degrees

Question 13

What charges do complexes have?

Answer 13

= total oxidation state
= total oxidation state= total oxidation state - totoal oxidation state of ligands

Question 14

What is haemogloblin?

Answer 14

= multidentate ligand’haem’
= fe ion in the middle, protein used to transport blood
= octahedral
= 4 of the nitrigens come from the haem ligand, one of them comes from the large protein globin
final comes from an oxygen or a waterm

Question 15

How does haemogliin work?

Answer 15

= oxygen substitutes, the water ligand in the lungs, where oxygen conc is high to form oxyhaemoglobin,
= gives up an oxygne, water takes the place, and returns to lungs

Question 16

What does CO do to haemoglobin?

Answer 16

= inhaled the water lingand is replaced by CO bonds so strongly it cannot be readily replaced by oxygen and water
= oxygen starvatin so is posinious

Question 17

Can optical isomerism be shown for complex ions?

Answer 17

= yes

Question 18

How can complex ions show e/z isomerism?

Answer 18

= octahedral complexes with 4 ligands of the same type and 2 ligands of a different type can show e/z isomerism
= if the 2 different ligands are opposited to eachother trans isomerism
= if the 2 ligands are adjacent they are cis isomerism

Question 19

How do sqaure planar complexes show cis trans isomerism?

Answer 19

= sqaure planar ligands with 2 ligands of the samer type and 2 ligands of different types, can show this
= if the 2 different ligands are opposite sides this is trans
= if the 2 different ligands are on the same side it is cis

Question 20

How does d orbital splitting works?

Answer 20

= the d subshell is split into 2 when ligands bond with metal ion
= orbitals gain energy so there is a energy gap
= when electrons absorb light energy, some move from the lowest energy level to higher energy orbotals
= in order for this to happen the light must equal ^E

Question 21

what does the size of the energy gap between d orbitals depends on?

Answer 21

= central metal ions
= oxidation state
= type of light
= coordination number

Question 22

what formula is used to calculate the energy absorbed by the electrons?

Answer 22

= change in energ
= plancks constanr x frequency of light = speed of light/wave length of lught absorbed

Question 23

How are coloured complexes formed?

Answer 23

= colour arrises from electronic transitions between ground state to excited states, between different d orbitals
= some visible light is absorbed, to raise electrons to a higher energy level, light not absorbed is transmitted and gives colour

Question 24

What colour does [Cu(H2O)6]2+ show?

Answer 24

= absorbs frequencies, that produce red light, show light blue cyan colour

Question 25

What colours do complexes that have a full or empty 3d subshell show?

Answer 25

= no electrons can raise to a higher energy level, this means these are seen as white or colourless

Question 26

What does the colpir of complex iosn depends on?

Answer 26

= determined by energy change = by chanhe of pxidation state = change of numner of ligands and change un lugands

Question 27

How can transition metal ion complexes be anylysed?

Answer 27

= colorimetry = colours seen are compliments of the colours a bsorbed by solution = whrn white light hits the transition metals, one frequency is absorbed = observed the opposiye has been absorbed

Question 28

What does calromtery depend on?

Answer 28

= add appropiate ligand to intensity the colour = make solutions of known concentrations] = measure absorbance and transmission = plot graph of absorprtion vs transmission = measure absorbance of unkown and compare

Question 29

How can the colour be changed?

Answer 29

= changing a ligand, changing coordination number, will alter the energy split between d orbitals, changing the energy change and the frequency of light absorbed

Question 30

Why do we use a filter in the calorimeter?

Answer 30

= coloured filter = colour of the filter is chosen to allow wavelength of light, through that would most likley be absorbed by the coloured solution