INORGANIC Part 10 3d block TRANSITION METALS sub–index: 10.1–10.2
Introduction 3d–block Transition Metals * 10.3
Scandium
* 10.4 Titanium * 10.5
Vanadium * 10.6 Chromium
* 10.7 Manganese * 10.8
Iron * 10.9 Cobalt
* 10.10 Nickel
* 10.11 Copper * 10.12
Zinc
* 10.13 Other Transition Metals e.g. Ag and Pt * Appendix 1.
Hydrated salts, acidity of
hexa–aqua ions * Appendix 2. Complexes
& ligands * Appendix 3. Complexes and isomerism * Appendix 4.
Electron configuration & colour theory * Appendix 5. Redox
equations, feasibility, Eø * Appendix 6.
Catalysis * Appendix 7.
Redox
equations
* Appendix 8. Stability Constants and entropy
changes *
Appendix 9. Colorimetric analysis
and complex ion formula * Appendix 10 3d block
– extended data
* Appendix 11 Some 3d–block compounds, complexes, oxidation states
& electrode potentials * Appendix 12
Hydroxide complex precipitate 'pictures',
formulae and equations
Advanced
Level Inorganic Chemistry Periodic Table Index *
Part 1
Periodic Table history
* Part 2
Electron configurations, spectroscopy,
hydrogen spectrum,
ionisation energies *
Part 3
Period 1 survey H to He *
Part 4
Period 2 survey Li to Ne * Part
5 Period 3 survey Na to Ar *
Part 6
Period 4 survey K to Kr and important trends down a
group *
Part 7
s–block Groups 1/2 Alkali Metals/Alkaline Earth Metals *
Part 8
p–block Groups 3/13 to 0/18 *
Part 9
Group 7/17 The Halogens *
Part 10
3d block elements & Transition Metal Series
*
Part 11
Group & Series data & periodicity plots * All
11 Parts have
their own sub–indexes near the top of the pages
10.10. Chemistry
of Nickel Ni, Z=28, 1s22s22p63s23p63d84s2
data comparison of nickel
with the other members of the 3d–block and transition metals
Z
and symbol |
21
Sc |
22
Ti |
23
V |
24
Cr |
25
Mn |
26
Fe |
27
Co |
28
Ni |
29
Cu |
30
Zn |
property\name |
scandium |
titanium |
vanadium |
chromium |
manganese |
iron |
cobalt |
nickel |
copper |
zinc |
melting
point/oC |
1541 |
1668 |
1910 |
1857 |
1246 |
1538 |
1495 |
1455 |
1083 |
420 |
density/gcm–3 |
2.99 |
4.54 |
6.11 |
7.19 |
7.33 |
7.87 |
8.90 |
8.90 |
8.92 |
7.13 |
atomic
radius/pm |
161 |
145 |
132 |
125 |
124 |
124 |
125 |
125 |
128 |
133 |
M2+
ionic radius/pm |
na |
90 |
88 |
84 |
80 |
76 |
74 |
72 |
69 |
74 |
M3+
ionic radius/pm |
81 |
76 |
74 |
69 |
66 |
64 |
63 |
62 |
na |
na |
common oxidation
states |
+3
only |
+2,3,4 |
+2,3,4,5 |
+2,3,6 |
+2,3,4,6,7 |
+2,3,6 |
+2,3 |
+2,+3 |
+1,2 |
+2
only |
outer electron config. [Ar]... |
3d14s2 |
3d24s2 |
3d34s2 |
3d54s1 |
3d54s2 |
3d64s2 |
3d74s2 |
3d84s2 |
3d104s1 |
3d104s2 |
Elect.
pot. M(s)/M2+(aq) |
na |
–1.63V |
–1.18V |
–0.90V |
–1.18V |
–0.44V |
–0.28V |
–0.26V |
+0.34V |
–0.76V |
Elect.
pot. M(s)/M3+(aq) |
–2.03V |
–1.21V |
–0.85V |
–0.74V |
–0.28V |
–0.04V |
+0.40 |
na |
na |
na |
Elect.
pot. M2+(aq)/M3+(aq) |
na |
–0.37V |
–0.26V |
–0.42V |
+1.52V |
+0.77V |
+1.87V |
na |
na |
na |
Elect.
pot. = standard electrode potential data for nickel
(EØ at 298K/25oC, 101kPa/1 atm.)
na = data not applicable to nickel
Extended data table for NICKEL
property of nickel/unit |
value for Ni |
melting
point Ni/oC |
1455 |
boiling
point Ni/oC |
2730 |
density Ni/gcm–3 |
8.90 |
1st
Ionisation Energy Ni/kJmol–1 |
737 |
2nd
IE/kJmol–1 |
1753 |
3rd
IE/kJmol–1 |
3393 |
4th
IE/kJmol–1 |
5300 |
5th
IE/kJmol–1 |
7280 |
atomic
radius Ni/pm |
125 |
Ni2+
ionic radius/pm |
72 |
Relative polarising power Ni2+ ion |
2.8 |
Ni3+
ionic radius/pm |
62 |
Relative polarising power Ni3+ ion |
4.8 |
oxidation
states of Ni,
less common/stable |
+2, +3 |
simple electron
configuration of Ni |
2,8,16,2 |
outer electrons of Ni |
[Ar]3d84s2 |
Electrode potential Ni(s)/Ni2+(aq) |
–0.26V |
Electrode potential Ni(s)/Ni3+(aq) |
na |
Electrode potential Ni2+(aq)/Ni3+(aq) |
na |
Electronegativity of Ni |
1.91 |
The
Chemistry of
NICKEL
Pd |
s block |
d blocks
(3d block
nickel) and
f
blocks of
metallic elements |
p block elements |
Gp1 |
Gp2 |
Gp3/13 |
Gp4/14 |
Gp5/15 |
Gp6/16 |
Gp7/17 |
Gp0/18 |
1 |
1H
|
2He |
2 |
3Li |
4Be |
The modern Periodic Table of Elements
ZSymbol, z = atomic or proton
number
3d
block of metallic elements: Scandium to Zinc
focus on nickel |
5B |
6C |
7N |
8O |
9F |
10Ne |
3 |
11Na |
12Mg |
13Al |
14Si |
15P |
16S |
17Cl |
18Ar |
4 |
19K |
20Ca |
21Sc
[Ar]3d14s2
scandium |
22Ti
[Ar]3d24s2
titanium |
23V
[Ar] 3d34s2
vanadium |
24Cr
[Ar] 3d54s1
chromium |
25Mn
[Ar] 3d54s2
manganese |
26Fe
[Ar] 3d64s2
iron |
27Co
[Ar] 3d74s2
cobalt |
28Ni
[Ar] 3d84s2
nickel |
29Cu
[Ar] 3d104s1
copper |
30Zn
[Ar] 3d104s2
zinc |
31Ga |
32Ge |
33As |
34Se |
35Br |
36Kr |
5 |
37Rb |
38Sr |
39Y |
40Zr |
41Nb |
42Mo |
43Tc |
44Ru |
45Rh |
46Pd |
47Ag |
48Cd |
49In |
50Sn |
51Sb |
52Te |
53I |
54Xe |
6 |
55Cs |
56Ba |
57,58-71 |
72Hf |
73Ta |
74W |
75Re |
76Os |
77Ir |
78Pt |
79Au |
80Hg |
81Tl |
82Pb |
83Bi |
84Po |
85At |
86Rn |
7 |
87Fr |
88Ra |
89,90-103 |
104Rf |
105Db |
106Sg |
107Bh |
108Hs |
109Mt |
110Ds |
111Rg |
112Cn |
113Uut |
114Fl |
115Uup |
116Lv |
117Uus |
118Uuo |
|
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*********** |
************ |
************ |
************** |
********** |
********** |
********** |
********** |
********** |
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-
The
electrode potential chart highlights the values for various
oxidation states of nickel.
-
NICKEL(II) CHEMISTRY
-
In aqueous solution
nickel forms the green stable hexaaqua nickel(II) ion, [Ni(H2O)6]2+(aq) from
eg nickel(II) chloride solution NiCl2(aq) or nickel(II)
sulfate NiSO4(aq), both of which are suitable for laboratory
experiments for investigating the aqueous chemistry of the nickel(II)
ion..
-
With alkalis sodium
hydroxide or ammonia,
nickel(II) ions produce the hydrated
nickel(II) hydroxide
green?
precipitate. There is no further reaction with excess
of NaOH, but see further down for excess NH3.
-
With alkaline aqueous
sodium carbonate solutions,
nickel(II) ions produces a precipitate of green ppt. of nickel(II) carbonate.
-
With excess aqueous
ammonia the blue hexammine complex ion is formed from the
hexaaquanickel(II) ion – a typical ligand substitution reaction giving
the hexaamminenickel(II) ion:
-
[Ni(H2O)6]2+(aq)
+ 6NH3(aq)
[Ni(NH3)6]2+(aq)
+ 6H2O(l)
-
The two nickel(II) complexes are
octahedral in shape with a co-ordination number of 6.
-
The overall charge on the
nickel(II) hydroxide complex remains 2+ because both ligands are
electrically neutral.
-
This is another example of a
nickel complex ligand exchange reaction where six ammonia molecules
replace six water molecules.
-
Kstab = {[Ni(NH3)6]2+(aq)}
/ {[Ni(H2O)6]2+(aq)} [NH3(aq)]6
-
Kstab =
4.8 x 107 mol–6 dm18 [lg(Kstab)
= 7.7]
-
You can write
equation of the ammine complex from the dissolving of nickel(II) hydroxide
precipitate.
-
Ligand substitution may be
incomplete, so, with lower
concentrations of ammonia the pale blue complex can also have the structure
[Ni(H2O)2(NH3)4]2+
-
The hexaaquanickel(II)
ion also forms complexes with other amine ligands
-
e.g. the bidentate
ligand 1,2–diaminoethane (H2N–CH2–CH2–NH2), often abbreviated to
en from its old trivial name of ethylenediamine). Each
of the lone pairs of electrons on the nitrogen atoms can form a
co-ordinate bond
-
[Ni(H2O)6]2+(aq)
+ 3en(aq)
[Ni(en)3]2+(aq)
+ 6H2O(l)
-
This is an example of a
chelation substitution reaction where a bidentate or
multidentate ligand displaces a numerically greater monodentate
(unidentate) ligands.
-
The resulting nickel complex
is described as an example of a chelate.
-
Kstab
= {[Ni(en)3]2+(aq)}
/ {[Ni(H2O)6]2+(aq)}
{[en(aq)]3}
-
Kstab
= 2.0 x 1018 mol–3 dm9 [lg(Kstab)
= 18.3]
-
The reaction is almost
completely 100% to the right.
-
Notice that the Kstab
is greater than the Kstab for the formation of the
ammine complex, so you can correctly predict that the following
ligand exchange will take place ...
-
[Ni(NH3)6]2+(aq)
+ 3en(aq)
[Ni(en)3]2+(aq)
+ 6NH3(aq)
-
I've used en for simplicity,
but the formula of the complex formed is [Ni(H3NCH2CH2NH3)3]2+
-
Although then enthalpy
changes for these reactions are similar, because a similar
number of similar covalent bonds are broken or made, the release
of the larger number of smaller molecules leads to a large
increase in entropy (a large positive
ΔS).
-
This makes the free energy
change, calculated from
ΔG = ΔH - TΔS, more negative, therefore more feasible for
these nickel complex reactions.
-
The complex with EDTA is
also readily formed. EDTA is an even more powerful chelating agent
with an extremely high Kstab values.
-
[Ni(H2O)6]2+(aq)
+ EDTA4–(aq) ===> [Ni(EDTA)]2–(aq)
+ 6H2O(l)
-
Kstab
= {[Ni(EDTA)3]2–(aq)}
/ {[Ni(H2O)6]2+(aq)}
{[EDTA4–(aq)]}
-
Kstab =
1.0 x 1019 mol–1 dm3 [lg(Kstab)
= 19.0]
-
Note that Kstab
for the same ion tend to increase the greater the chelating power of
an individual ligand in terms of the ligand bond formed – mainly due
to the increase in entropy as more particles are formed by the
polydentate ligands displacing the unidentate ligands.
-
e.g. for the same
nickel(II) ion Kstab(EDTA) > Kstab(en)
> Kstab(NH3)
-
That is from left to right in the
sequence, the entropy change decreases, multidentate > bidentate >
monodentate (unidentate)
-
VIEW ppts. with OH–, NH3
and CO32–, & complexes,
if any, with
excess reagent.
-
Other complexes of nickel
-
Nickel carbonyl,
Ni(CO)4, is a neutral complex tetrahedrally shaped covalent
molecule. Note (i) nickel is in a zero oxidation state and (ii) the ligand CO also acts as ligand with haemoglobin
(hemoglobin) in carbon monoxide poisoning.
-
Ni2+ forms
the tetrachloronickelate(II) ion, [NiCl4]2–, a
tetrahedral anionic complex
with the chloride ion ligand (Cl–).
-
[Ni(H2O)6]2+(aq) +
4Cl–(aq)
==> [NiCl4]2–(aq) + 6H2O(l)
-
In this ligand exchange
reaction, the nickel(II) complex ion shape changes from
octahedral to tetrahedral, the co-ordination number changes from
6 to 4, but the oxidation state of nickel remains at +2. The
overall electrical charge on the chloro complex is 2- (from
2+/+2 and 4x-1).
-
Its likely that the more
bulky chloride ion (radius Cl > C) 'forces' the formation of the
tetrahedral shape rather than a square planar shaped complex in the
reaction described below.
-
Kstab
= {[NiCl4]2–(aq)}
/ {[Ni(H2O)6]2+(aq)}
[Cl–(aq)]4
-
Kstab
= ? mol4 dm–12 [lg(Kstab)
= ?]
-
Ni2+ forms
the tetracyanonickelate(II) ion, [Ni(CN)4]2–, a
square planar anionic complex
with the cyanide ion (CN–).
-
[Ni(H2O)6]2+(aq) +
4CN–(aq)
==> [NiCN4]2–(aq) + 6H2O(l)
-
Similar to above, in this
ligand exchange reaction, the nickel(II) complex ion shape
changes from octahedral to square planar, the co-ordination
number changes from 6 to 4, but the oxidation state of nickel
remains at +2. The overall electrical charge on the chloro
complex is 2- (from 2+/+2 and 4x-1).
-
Kstab
= {[NiCN4]2–(aq)}
/ {[Ni(H2O)6]2+(aq)}
[CN–(aq)]4
-
Kstab
= 2 x 1031 mol4 dm–12
[lg(Kstab) = 31.3]
-
Summary of some
complexes–compounds & oxidation states of nickel compared to other
3d–block elements
-
An example of the catalytic action
of nickel metal.
-

-
An example of nickel acting as a
heterogeneous catalysis is illustrated above, the hydrogenation of alkenes
(e.g. ethene + hydrogen ===> ethane). An extremely important process
in the food industry or converting unsaturated oils into hydrogenated solid
fats.
-
Nickel is the solid phase catalyst and
the reactant gases in the different gaseous phase.
-
In terms of activation energies, with
reference to the reaction profile below:
-
(1) ==> (2) is represented by
Ea1, the
absorption of the reactant molecules onto the catalyst surface to form the
intermediate state between nickel and the adsorbed gases..
-
(3) represents the minimum potential
energy trough where the molecules are adsorbed onto the catalyst surface.
-
(2) ==> (3-5) is represented by
Ea2 the
formation of the products form the intermediate absorbed states of the
molecules.
-

-
A two stage reaction profile for a
catalytic cycle (Ea = activation energy)
-
This sort of diagram is most
applicable to homogeneous catalysis where definite intermediates are
formed, but in general principle it applies to heterogeneous catalysis
too where the adsorption (particularly chemical) is equivalent to
forming a transition state or complex.
-
Ea1 is the activation energy leading to the formation of an
intermediate complex between nickel and the adsorbed gases.
-
Ea2 is the activation energy for the change of the
intermediate complex into product (ethane).
-
Ea3 is the activation energy of the uncatalysed reaction
between nickel and hydrogen.
PLEASE NOTE this page on the 3d
block transition metal nickel is for Advanced A Level students ONLY!
Therefore it is IMPORTANT for GCSE/IGCSE/O Level
students studying iron chemistry to go to ...
GCSE/IGCSE
Periodic Table Revision Notes or GCSE/IGCSE Transition Metals Revision Notes
including nickel
physical and chemical
properties of the 3d block transition metal nickel, oxidation
and reduction reactions of nickel ions, outer electronic
configurations of nickel, principal oxidation states of
nickel,
shapes of nickel's complexes, octahedral complexes of nickel,
tetrahedral complexes of nickel, square planar complexes of
nickel, stability data for nickel's complexes, aqueous chemistry
of nickel ions, redox reactions of nickel ions, physical
properties of nickel, melting point of nickel, boiling point of
nickel, electronegativity of nickel, density of nickel, atomic radius
of nickel, ion radius of nickel, ionic radii of nickel's ions, common
oxidation states of nickel, standard electrode potential data
for nickel, ionisation energies of nickel, polarising power of
nickel
ions, industrial applications of nickel compounds, chemical
properties of nickel compounds, why are nickel complexes
coloured?, isomerism in the complexes of nickel, formulae of
nickel compounds, tests for nickel ions keywords redox reactions ligand
substitution displacement balanced equations
formula complex ions complexes ligand exchange reactions redox reactions ligands
colours oxidation states: nickel ions Ni(0) Ni2+ Ni(+2) Ni(II) NiCl2
NiSO4 Ni2+ + 2OH– ==> Ni(OH)2 Ni2+ + CO32– ==> NiCO3 Ni2+ + 2HCO3– ==> NiCO3 + 4H2O +
CO2 [Ni(H2O)6]2+ + 6 NH3 [Ni(NH3)6]2+ + 6H2O [Ni(H2O)6]2+ + 6NH3 ==>
[Ni(NH3)6]2+ + 6 H2O Kstab = {[Ni(NH3)6]2+} / {[Ni(H2O)6] 2+} [NH3]6 Ni(OH)2 +
6NH3 [Ni(NH3)6]2+ + 2OH– [Ni(H2O)6]2+ + 3en ===> [Ni(en)3]2+ + 6H2O Kstab = {[Ni
(en)3]2+} / {[Ni(H2O)6]2+} {[en]3} [Ni(H2O)6]2+ + EDTA4– ===> [Ni(EDTA)]2– +
6H2O Kstab = {[Ni(EDTA)3]2–} / {[Ni (H2O)6]2+} {[EDTA4–]}[Ni(H2O)6]2+ + 4 Cl–
==> [NiCl4]2– + 6H2O Kstab = {[NiCl4]2–} / {[Ni(H2O)6]2+} [Cl–]4 [Ni(H2O)6]2+ +
4 CN– ==> [NiCN4]2– + 6H2O Kstab = {[NiCN4]2–} / {[Ni(H2O)6]2+} [CN–]4 Kstab = 2
x 1031 mol4 dm–12 [lg(Kstab) = 31.3] oxidation states of nickel, redox reactions
of nickel, ligand substitution displacement reactions of nickel, balanced
equations of nickel chemistry, formula of nickel complex ions, shapes colours of
nickel complexes Na2CO3 NaOH NH3 nickel chemistry
for AQA AS chemistry, nickel chemistry
for Edexcel A level AS chemistry, nickel chemistry for A level OCR AS chemistry A,
nickel chemistry for OCR Salters AS chemistry B,
nickel chemistry for AQA A level chemistry, nickel chemistry for A level Edexcel A level chemistry,
nickel chemistry for OCR A level chemistry
A, nickel chemistry for A level OCR Salters A
level chemistry B nickel chemistry for US Honours grade 11 grade 12 nickel
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notes on nickel chemistry for schools colleges academies science course tutors images
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A level chemistry notes on nickel chemistry for OCR A level chemistry
notes WJEC A level chemistry notes on nickel chemistry CCEA/CEA A level
chemistry notes on nickel chemistry for university entrance examinations
biological role of cobalt nickel is unknown, nickel(II) chemistry, shape and
formula of complexes of nickel(II) Ni2+, complexes of nickel with ammonia,
oxidation of nickel(II) ion Ni2+ to the nickel(III) ion Ni3+, reactions of the
nickel(II) ion Ni2+ with hydroxide ion, structure formula and shape of nickel
carbonyl, colour and structure of nickel(III) Ni3+ complexes, formula of EDTA
complexes of nickel, tetrahedral complexes of nickel with chloride ion ligands,
octahedral complexes of nickel(II) ion Ni2+ with cyanide and water ligands,
octahedral complexes of nickel(III) Ni3+
Scandium
* Titanium * Vanadium
* Chromium
* Manganese * Iron * Cobalt
* Nickel
* Copper *
Zinc
* Silver & Platinum
Introduction 3d–block Transition Metals * Appendix
1.
Hydrated salts, acidity of
hexa–aqua ions * Appendix 2. Complexes
& ligands * Appendix 3. Complexes and isomerism * Appendix 4.
Electron configuration & colour theory * Appendix 5. Redox
equations, feasibility, Eø * Appendix 6.
Catalysis * Appendix 7.
Redox
equations
* Appendix 8. Stability Constants and entropy
changes *
Appendix 9. Colorimetric analysis
and complex ion formula * Appendix 10 3d block
– extended data
* Appendix 11 Some 3d–block compounds, complexes, oxidation states
& electrode potentials * Appendix 12
Hydroxide complex precipitate 'pictures',
formulae and equations
PLEASE NOTE this page on the 3d
block transition metal nickel is for Advanced A Level students ONLY!
Therefore it is IMPORTANT for GCSE/IGCSE/O Level
students studying iron chemistry to go to ...
GCSE/IGCSE
Periodic Table Revision Notes or GCSE/IGCSE Transition Metals Revision Notes
including nickel
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