Chemistry > d and f Block Elements > 3.0 General Trends in properties of First Row Elements
d and f Block Elements
1.0 General Introduction and Electronic Configuration
2.0 Occurrence and General Characteristics of Transition Elements
3.0 General Trends in properties of First Row Elements
3.1 Ionisation Enthalpy
3.2 Oxidation State
3.3 Atomic and Ionic Radii
3.4 Colour
3.5 Catalytic properties
3.6 Magnetic Properties
3.7 Formation of Interstitial Compounds
3.8 Alloy Formation
4.0 Potassium dichromate
5.0 Potassium permanganate
5.1 Properties of potassium permanganate
5.2 Structure of manganate ion and permanganate ion
5.3 Disproportion of an oxidation state
5.4 Uses
6.0 F-Block Elements - Introduction
7.0 Lanthanoid Series
7.1 Position of Lanthanoid Series
7.2 Electronic configuration of lanthanoids
7.3 Oxidation States
7.4 Chemical Reactivity of Lanthanides
8.0 Lanthanoid Contraction and its consequence
9.0 Actinoids Series
9.1 Position of Actinoids in periodic table
9.2 Electronic Configuration of actinoids
9.3 Oxidation states of actinoids
10.0 Comparison between lanthanoids and actinoids
3.2 Oxidation State
3.2 Oxidation State
3.3 Atomic and Ionic Radii
3.4 Colour
3.5 Catalytic properties
3.6 Magnetic Properties
3.7 Formation of Interstitial Compounds
3.8 Alloy Formation
5.2 Structure of manganate ion and permanganate ion
5.3 Disproportion of an oxidation state
5.4 Uses
7.2 Electronic configuration of lanthanoids
7.3 Oxidation States
7.4 Chemical Reactivity of Lanthanides
9.2 Electronic Configuration of actinoids
9.3 Oxidation states of actinoids
- Energies of $ns$ and $(n-1)d$ subshell are almost same.
- These elements show variable oxidation states from $+1$ to $+7$.
- $Sc$ ($3{d^1}{\text{ 4}}{{\text{s}}^2}$) show $+2$ and $+3$ oxidation states where as $Mn$ ($3{d^5}{\text{ 4}}{{\text{s}}^2}$) show maximum oxidation states.
- From $Fe$ and onwards number of unpaired electrons in $3d$ orbitals decreases which decreases the number of oxidation States.
- As the no. of unpaired electrons in $3d$ orbitals increases the no. of oxidation states also increases.
- Scandium $(21)$ show $+2$ ($3{d^1}$) and $+3$ ($3{d^0}$) oxidation states, out of which $+3$ is more stable (electronic configuration), it form compounds in %+3% oxidation states.
- Titanium shows $+2$ ($3{d^2}$), $+3$ ($3{d^1}$) and $+4$ ($3{d^0}$), oxidation states, among these $+4$ is more stable.
- Vanadium ($3{d^3}{\text{ 4}}{{\text{s}}^2}$) from $+2$ ($3{d^3}$), $+3$ ($3{d^2}$) and $+4$ ($3{d^1}$) and $+5$ ($3{d^0}$) oxidation states and $+5$ is most stable.
- Chromium ($3{d^5}{\text{ 4}}{{\text{s}}^1}$) form $+1$ ($3{d^5}$),+2($3{d^4}$), $+3$ ($3{d^3}$), $+4$ ($3{d^2}$), $+5$ ($3{d^1}$) and $+6$ ($3{d^0}$) oxidation states.
- In chromium $+1$ ($3{d^5}$) is more stable due to half filled nature of $3d$ but $Cr$ does not form stable compounds in the oxidation states but it forms complexes in this state.
- Salts of $Cr$ in $+2$ state are chromus salt (for example. $CrC{l_2}$, $CrS{O_4}$).
- The salts in $+3$ oxidation state are called chromic or Chromium salts ($CrC{l_3}$).
- $+4$ and $+5$ are unstable but $+6$ is more stable and form stable salts like ${K_2}Cr{O_4}$, ${K_2}C{r_2}{O_7}$, $Cr{O_2}C{l_2}$.
- In $+6$ oxidation state $Cr$ acts as good oxidizing agent (${K_2}C{r_2}{O_7}$).
- Manganese ($3{d^5}4{s^2}$) shows $+2$ and $+7$ oxidation states.
- $+2$ is more relatively stable due to half filled configuration of $3d$.
- Salts of $Mn$ in $+2$ oxidation states are called manganous or manganese salts ($MnC{l_2}$).
- $+3$ and $+5$ are unstable where as $+4$ is very stable ($Mn{O_2}$).
- $Mn$ forms Manganate (${K_2}Mn{O_4}$) in $+6$ oxidation state and permanganate in $+7$ ($KMn{O_4}$). $Mn$ $+7$ oxidation acts as good oxidizing agent.
- Iron ($3{d^6}4{s^2}$), Cobalt ($3{d^7}4{s^2}$) and Nickel ($3{d^8}4{s^2}$) shows $+2$ and $+3$ oxidation states.
- $+3$ oxidation state in $Fe$ is more as ferric and $+2$ is called ferrous which acts as reducing agents.
- Compounds in $+6$ oxidation states of $Fe$ are called ferrates (Pot-ferrate ${K_2}Fe{O_4}$). $+4$ and $+5$ are least stable.
- $+2$ oxidation state is more stable in cobalt and Nickel.
- $Cu$ ($3{d^{10}}4{s^1}$) show $+1$ and $+2$. Salts in $+1$ are cuprous and $+2$ are cupric salts, where as $Zn$ show only $+2$.
- Highest oxidation states of transition elements are found in flourides and oxides $(+8)$.
- Both $Os$ and $Rn$ form $+8$ ($Os{O_4}$).
- Most common oxidation state of these elements is $+2$. Ionic bonds are formed in $+2$ and $+3$ whereas covalent in higher oxidation states.
- Higher oxidation states are stabilized by highly electronegative atoms like $O$ and $F$ where as $0$ and $+1$ by ligands.
| Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn |
+2 | +2 +3 +4 | +2 +3 +4 +5 | +2 +3 +4 +5 +6 | +2 +3 +4 +6 +7 | +2 +3 +4 | +2 +3 +6 | +2 +3 +4 | +1 +2 | +2 |
