 Periodic
Table 3d block Scandium chemistry - Doc Brown's Chemistry Revising Advanced
Level Inorganic Chemistry Periodic Table
Revision Notes
Part 10. 3d block – Transition Metals –
10.3
Scandium Chemistry
Scandium is a member of
the 3d–block of elements BUT why isn't scandium a true transition metal?
Scandium cannot form an ion with an incomplete 3d sub–shell and is
therefore not a true transition element. Scandium's chemistry is
determined solely by the formation of compounds in its +3 oxidation
state, but it does form many complexes, though not as many as other
transition metals.
principal oxidation states of
scandium, redox reactions of scandium, ligand substitution displacement
reactions of scandium, balanced equations of scandium chemistry, formula
of scandium complex ions, shapes colours of scandium complexes, formula
of compounds
GCSE/IGCSE
Periodic Table Revision Notes *
GCSE/IGCSE Transition Metals Revision Notes
|
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
10.3. Chemistry
of Scandium Sc, Z=21,
1s22s22p63s23p63d14s2
data comparison of scandium
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 scandium
(EØ at 298K/25oC, 101kPa/1 atm.)
na = data not applicable to scandium
Extended data table for SCANDIUM
property of scandium/unit |
value for Sc |
melting
point/oC |
1541 |
boiling
point/oC |
2836 |
density/gcm–3 |
2.99 |
1st
Ionisation Energy/kJmol–1 |
631 |
2nd
IE/kJmol–1 |
1235 |
3rd
IE/kJmol–1 |
2389 |
4th
IE/kJmol–1 |
7089 |
5th
IE/kJmol–1 |
8844 |
Sc atomic
radius/pm |
161 |
Sc3+
ionic radius/pm |
81 |
Relative polarising power Sc3+ ion |
3.7 |
oxidation
state of Sc |
+3
only |
simple electron
configuration of Zn |
2,8,9,2 |
outer electrons of Sc |
[Ar]3d14s2 |
Electrode potential Sc(s)/Sc3+(aq) |
–2.03V |
Electronegativity of Sc |
1.36 |
-
Uses of SCANDIUM
-
Scandium is a silvery–white metal
and not a particularly important element but does have some uses.
-
Scandium oxide, Sc2O3,
is used in electronic components.
-
Scandium iodide, ScI3,
is used in high intensity light–bulbs.
-
Scandium carbide, ScC, is a
hardening agent for titanium carbide, making it the second hardest
substance known.
The Chemistry
of
SCANDIUM
Pd |
s block |
d blocks (3d
block
scandium)
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 scandium |
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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-
The
electrode potential chart highlights the value for the one positive
oxidation state of scandium.
-
Scandium's
chemistry is entirely based on the +3 oxidation state (Sc3+), the result of losing the
outer 3d and 4s electrons.
-
So it forms a typical
series of binary compounds with non–metals e.g. Sc2O3, ScCl3 etc.
-
Scandium dissolves in
acids to form salts e.g. scandium chloride from hydrochloric acid.
-
2Sc(s) + 6HCl(aq) ==> 2ScCl3(aq)
+ 3H2(g)
-
Note that the Roman numerals
(III) are NOT needed in the name, since only one oxidation state is
possible for scandium and you would be expected to know that.
-
With oxygen scandium forms a
white basic oxide, scandium oxide Sc2O3,
-
2Sc(s) + 3O2(g)
==> Sc2O3(s)
-
which dissolves in acids to
form colourless solutions of the respective salt e.g.
-
Sc2O3(s)
+ 6HCl(aq) ==> 2ScCl3(aq) + 3H2O(l)
(scandium chloride)
-
Sc2O3(s)
+ 3H2SO4(aq) ==> Sc2(SO4)3(aq)
+ 3H2O(l)
(scandium sulfate)
-
Sc2O3(s)
+ 6HNO3(aq) ==> 2Sc(NO3)3(aq) + 3H2O(l)
(scandium nitrate)
-
The scandium(III) ion, Sc3+
ion, [Sc(H2O)6)]3+
has an empty sub–shell, 3d0, which does not allow the
electronic transitions which account for the colour in transition
metal compounds.
-
The aqueous
octahedral hexaaqua ion of scandium,
[Sc(H2O)6]3+ is therefore colourless
(shown as grey in the diagram!) and with no other oxidation state possible i.e. no ion with an
incomplete 3d sub–shell with at least one electron, although a
member of the 3d–block, scandium is NOT a true transition metal.
-
With
alkali, the aqueous scandium ion
Sc3+ forms a white gelatinous precipitate of hydrated scandium hydroxide, Sc(OH)3,
-
Sc3+(aq) +
3OH–(aq) ==> Sc(OH)3(s)
-
Scandium hydroxide is
a basic hydroxide and not
amphoteric i.e. it does not dissolve in excess alkali, but scandium
hydroxide readily
dissolves in acids to form salts e.g. to form scandium chloride,
scandium nitrate or scandium sulfate ...
-
Sc(OH)3(s)
+ 3HCl(aq) ==> ScCl3(aq) + 3H2O(l)
-
Sc(OH)3(s)
+ 3HNO3(aq) ==> Sc(NO3)3(aq) +
3H2O(l)
-
2Sc(OH)3(s)
+ 3H2SO4(aq) ==> Sc2(SO4)3(aq)
+ 6H2O(l)
-
The chemistry of
scandium is not very colourful or exciting!
-
The equations are
similar to those for aluminium hydroxide i.e. you can substitute Al for
Sc.
-
Summary of some
complexes–compounds & oxidation state of scandium compared to other
3d–block elements
-
–
keywords redox reactions ligand
substitution displacement balanced equations
formula complex ions complexes ligands colours oxidation states: scandium ions
Sc(0) Sc(III) Sc(+3) Sc3+ [Sc(H2O)]3+ 2Sc + 6 HCl ==> 2 ScCl3 + 3H2 2Sc + 3O2
==> Sc2O3 Sc2O3 + 6 HCl ==> 2ScCl3 + 3H2O Sc2O3 + 3 H2SO4 ==> Sc2(SO4)3 +
3H2O Sc2O3 + 6 HNO3 ==> 2Sc(NO3)3 + 3H2O Sc3+ + 3OH– ==> Sc(OH)3 Sc(OH)3 + 3HCl
==> ScCl3 + 3H2O Sc(OH)3 + 3HNO3 ==> Sc(NO3)3 + 3H2O 2Sc(OH)3 + 3H2SO4 ==>
Sc2(SO4)3 + 6H2O [Sc(OH)3(H2O)3] oxidation states of scandium, redox reactions
of scandium, ligand substitution displacement reactions of scandium, balanced
equations of scandium chemistry, formula of scandium complex ions, shapes
colours of scandium complexes
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
TOP OF PAGE
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