1.3 transition metals Flashcards

1
Q

what block are the transition metals

A

d

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2
Q

do transition metals have full d subshells?

A

no, only partially filled

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3
Q

which principle does the filling of d orbitals follow

A

the aufbau

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4
Q

what two transition metals are an exception for filling up following the aufbau principle, and why

A

chromium and copper
they have a special stability associated with the d subsjell being half filled or completely filled

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5
Q

which electrons are lost if atoms from the first row of transition metals form ions

A

the 4s electrons. not the 3d!

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6
Q

when is an element said to be in a particular oxidation state

A

when it has a specific oxidation number

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7
Q

what is the oxidation number of uncombined elements

A

0

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8
Q

what is the oxidation number of ions containing single atoms

A

one that is the same as the charge on the ion

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9
Q

what is the usual oxidation number of oxygen

A

-2

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10
Q

what is the usual oxidation number of hydrogen

A

1

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11
Q

what must the sum of all the oxidation numbers of all the atoms in a neutral atom add up to

A

0

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12
Q

what must the sum of all the oxidation numbers of all the atoms in a polyatomic ion be equal to

A

the charge on the ion

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13
Q

can a transition metal have different oxidation states in its compounds

A

yes

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14
Q

can the compounds of the same transitio nmetal in different oxidation states have different colours

A

yes they may

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15
Q

what can oxidation be defined as

A

an increase in oxidation number

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16
Q

what can reduction be considered as

A

a decrease in oxidation number

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17
Q

what can the changes in oxidation number of transition metals be used to determine

A

whether oxidation or reduction has occurred

18
Q

what compounds containing metals are often recognized as oxidising agents

A

those with high oxidation states

19
Q

which compounds containing are often recognized as reducing agents

A

those with low oxidation states

20
Q

what are ligands

A
  • negative ions
  • molecules with non bonding pairs
21
Q

how can ligands be classified

A

monodentate, bidentate, hexadentate

22
Q

is it possible to deduce the ligand classification from a formula or structure of the ligand or complex

A

unfortunately yes

23
Q

what is the coordination number

A

the total number of bonds from the ligands to the central transition metal

24
Q

when are d orbitals no longer degenerate

A

in a complex of a transition metal

25
Q

when does the splitting of d orbials to higher and lower energies occur

A

when the electrons present in the approaching ligands cause the electrons in the orbitals lying along the axes to be repelled

26
Q

what are strong field ligands

A

ligands that cause a large difference in energy between subsets of d orbitals

27
Q

what are weak field ligands

A

ligands that cause a small difference in energy between subsets of d orbitals

28
Q

how can ligands be placed

A

in order of their ability to split d orbitals

29
Q

what is the spectrochemical series

A

the order that ligands are placed according to their ability to split d orbitals

30
Q

how can the colours of many transition metal complexes be explained

A

in terms of d-d transitions

31
Q

when is light absorbed

A

when electrons in lower energy d orbital are promoted to d orbital of higher energy

32
Q

when is the complementary colour observed

A

when one light of one colour is absorbed

33
Q

when light of one colour is absorbed, what is observed

A

the complementary colour

34
Q

when do electrons transition to higher energy levels

A

when energy corresponding to the ultraviolet or visible regions of the electromagnetic spectrum is absorbed

35
Q

can transition metals act as catalysts

A

yes

36
Q

are heterogenous catalysts in different states to the reactants

A

yes

37
Q

how can heterogenous catalysts be explained

A

in terms of the formation of activated complexes and the adsorption of reactive molecules onto active sites

38
Q

what is the presence of unpaired d electrons or unfilled d orbitals thought to allow

A

activated complexes to form

39
Q

what can the formation of activated complexes provide

A

reaction pathways with lower activation energies compared to the uncatalysed reaction

40
Q

are homogenous catalysts in the same or different state as the reactants

A

same

41
Q

how can homogenous catalysts be explained

A

in terms of changing oxidation states with the formation of intermediate complexes