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Flashcards in TRANSITION METALS Deck (53)
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1
Q

define what transition metal is

A

D block elements forming one or more stable ions with incomplete D orbitals

2
Q

what properties do transition metals have

A
  • variable oxidation states (apart from Sc 3+ and Zn 2+)
  • form coloured compounds
  • used as catalysts
3
Q

when is iron used as a catalyst

A

HABER PROCESS

  • making ammonia
  • N2 (g) + 3H2 (g) –> 3NH2 (aq)

THIOSULFATE + IODIDE (Fe 3+)
- S2O8(2-) + Fe(2+) –> 2SO4(2-) + Fe(3+)
2Fe(3+) + 2I- –> I2 + 2Fe(2+)

4
Q

when is nickel used as a catalyst

A

HYDROGENATION
- margarine manufacture
- CH2CH2 + H2 –> CH3CH3
Ni / 150ºc

5
Q

when is Cu(2+) used as a catalyst

A

ZINC + SULFURIC ACID TO MAKE H2
- Zn + H2SO4 –> ZnSO4 + H2
Cu(2+)

6
Q

when is vanadium oxide used as a catalyst

A
CONTACT PROCESS ( step 2)
- making sulfuric acid
1. S (l) + O2 (g) --> SO2 (g)
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
*2. 2SO2 (g) + O2 (g)  2SO3 (g)
                                  V2O5
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
3. SO3 (g) + H2SO4 (l) --> H2S2O7 (l)
    H2S2O7 (l) + H20 (l) --> 2H2SO4 (l)
7
Q

why are trans. mets. good catalysts

A

partially filled d orbitals can be used to form bonds w/ ADsorbed reactant which helps reactions take place more easily

8
Q

define complex ion

A

a central metal ion co-ordinately bonded to one or more molecule / negative ion

9
Q

define ligand

A

a molecule/ion that donates a pair of e- to a central metal ion to form a co-ordinate bond

10
Q

define co-ordination number

A

the total number of co-ordinate bonds formed between the central metal ion + any ligands

11
Q

colour of Cu(2+) solution

A

pale blue

12
Q

copper + NaOH (aq)

observation and ionic equation

A

forms pale blue ppt - Cu(OH)2

Cu(2+) (aq) + 2OH(-) (aq) –> Cu(OH)2 (s)

13
Q

copper + XS NaOH (aq)

A

pale blue ppt - CU(OH)2, does NOT dissolve

14
Q

copper (+NH3) + XS NH3

A

forms a blue ppt at first - [Cu(OH)2(H2O)4]
but dissolves w/ XS to make a royal blue solution - Cu(NH3)4(H2O)2

             NH3 ACTS AS A BASE [Cu(H2O)6](2+) (aq) + 2NH3 (aq) --> [Cu(OH)2(H2O)4] (s) + 2NH4(+)

XS NH3
[Cu(OH)2(H2O)4] (s) + 4NH3 –> Cu(NH3)4(H2O)2 (aq) + 2H2O (l) + 2OH(-) (aq)

15
Q

copper + HCL

observation and ionic equation

A

blue solution –> yellow solution - CuCl4

Cu(H2O)6 + 4Cl(-) –> CuCl4 + 6H2O

16
Q

colour of iron (II) solution

A

pale green - Fe(2+)

17
Q

iron (II) + NaOH

observation and ionic equation

A

forms green ppt - Fe(OH)2

Fe(2+) (aq) + 2OH(-) (aq) –> Fe(OH)2 (s)

OXIDISES TO BROWN IN AIR - Fe(OH)3

18
Q

iron (II) + XS NaOH

A

green ppt - Fe(OH)2, does NOT dissolve

19
Q

colour iron (III) solution

A

pale yellow - Fe(3+)

20
Q

iron (III) + NaOH

observation and ionic equation

A

rusty brown ppt - Fe(OH)3

Fe(3+) (aq) + 3OH(-) (aq) –> Fe(OH)3 (s)

21
Q

iron (III) +XS NaOH

A

rusty brown ppt - Fe(OH)3, does NOT dissolve

22
Q

colour of manganese solution

A

pale pink - Mn(2+)

23
Q

manganese + NaOH

observation and ionic equation

A

light brown ppt - Mn(OH)2

Mn(2+) (aq) + 2OH(-) (aq) –> Mn(OH)2 (s)

darkens in air

24
Q

manganese + XS NaOH

A

light brown ppt - Mn(OH)2, does NOT dissolve

25
Q

colour of chromium solution

A

pale purple - Cr(3+)

unless SO4(2-) (green)

26
Q

chromium + NaOH

observation and ionic equation

A

grey green ppt - Cr(OH)3

Cr(3+) (aq) + 3OH- (aq) –> Cr(OH)3 (s)

27
Q

chromium + XS NaOH

observation and ionic equation

A

ppt dissolves to form a dark green solution Cr(OH)6

Cr(OH)3 (s) + 3OH- (aq) –> Cr(OH)6 (aq)

28
Q

chromium + XS NH3

A

purple solution - Cr(NH3)6

first forms grey green ppt - [Cr(OH)3(H2O)3]
dissolves on XS

29
Q

what angle do ligands need to be for CIS isomerism

A

90º

diff. planes

30
Q

what angle do ligands need to be for TRANS isomerism

A

180º

same planes

31
Q

define ligand substitution

A

when one ligand is replaced by another

32
Q

define optical isomers

A

non-superimposable mirror images

33
Q

define strereo isomerism

A

same structural formula but atoms occupy different positions in space

34
Q

how many bonds does a monodentate ligand form + examples

A

1 co-ordinate bond

H2O, Cl-, NH3

35
Q

how many bonds does a bidentate ligand form + examples

A

2 co-ordinate bonds

NH2CH2CH2NH2 (en)

36
Q

how many bonds does a multidentate ligand form + examples

A

several co-ordinate bonds

37
Q

EDTA uses

A
  • detergents
  • reduce hardness in water
  • food stabliser
  • medicine > prevent blood clotting
38
Q

how many lone pairs can EDTA donate

A

6

39
Q

what is the charge of EDTA

A

4-

40
Q

how many co-ordinate bonds can EDTA form

A

6 per molecule

41
Q

name the transition metal complex used in the treatment of cancer

A

cis-platin

42
Q

how may co-ordinate bonds can octahedral molecule have + bond angles

A

6

90º

43
Q

how may co-ordinate bonds can planar molecule have + bond angles

A

4

90º

44
Q

how may co-ordinate bonds can tetrahedral molecule have + bond angles

A

4

109.5º

45
Q

how does cis-platin work

A

binds to DNA in fast growing cells

in presence of cis-platin fast growing cancer cells have incorrectly copied DNA + so it prevents replication

46
Q

describe the bonding within a complex ion

A

ligand donates an e- pair

dative / co-ordinate bond is formed

47
Q

why is iron (III) more acidic than iron (II)

A
  • lone pair of e- on oxygen of H2O froms coordinate bond w/ iron ion
  • bc iron is pos charge it pulls e- density towards it
  • greater the charge, more pull on the e- in H2O molecule
  • therefore easier to lose H ion
  • therefore incr. in acidity
48
Q

why can ethane - 1,2 - diamine (en) be classified as bidentate and what is its structural formula

A
  • donates 2 lone pairs
  • one from each N atom
  • H2CH2CH2NH2
49
Q

why is the ligands exchange reaction not a redox reaction

A

no change in oxidation state as e- not gained or lost

*link to Q if given specific molecule

50
Q

when hexa-aqua copper reacts with Cl- why does the shape change from octahedral to tetrahedral

A

Cl- ligands are larger than H2O + are more neg charge. this makes tetrahedral more stable shape for the complex as there is less repulsion between ligands

51
Q

when hexa-aqua copper reacts with Cl- why does the coodination number go from 6 to 4

A

Cl- ligands are larger than H2O + are more neg charge. thus instead forms 4 co-ordinate bonds, this makes tetrahedral shape which is more stable shape for the complex as there is less repulsion between ligands

52
Q

write the ionic equation for hexa-aqua copper and HCL

A

Cu(H2O)6 (aq) + 4Cl- (aq) –> CuCl4 (aq) + 6H2O (l)

53
Q

what is ethane dioate

A

C2O4(2-)

BIDENTATE ligand