D & F Block FULL CHAPTER | Class 12th Inorganic Chemistry | Lakshya JEE

Lakshya JEE・2 minutes read

The text covers various aspects of the electron configurations, oxidation states, and properties of transition elements like lanthanides and actinides, emphasizing their colors, magnetic properties, and roles in chemical reactions and catalysis. Key points include the significance of unpaired electrons in determining properties, the color changes due to different electronic transitions, and the impact of oxidation states on reactivity and compound formation in transition elements, particularly lanthanides and actinides.

Insights

  • Electrons must be confined within the 3D sub cell in the 3D series.
  • Cerium plus 4 is an oxidant in chemistry, showcasing its role in reactions.
  • The chapter on Chemistry D&A Block is taught on Laksh JE's YouTube channel, providing accessible educational resources.
  • The F block consists of 28 elements, distinguishing it as an inner transition element.
  • Lanthanide series consists of 14 elements between Lantham and Half rule, highlighting its unique composition.
  • The concept of Lanthanide contraction explains the decrease in atomic sizes of D block elements, affecting their properties.
  • Metallic bonding and properties are influenced by unpaired electrons, with elements like chromium having distinct characteristics due to this.

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Recent questions

  • What is the significance of the Lanthanide series?

    The Lanthanide series consists of 14 elements between Lantham and Half rule. These elements are known for their colorful nature due to the presence of f electrons, resulting in vibrant solid and aqueous states. The DD and FF transitions in lanthanides cause color changes, with DD transitions leading to brighter colors. Lanthanides like ytterbium have multiple oxidation states, with some being trivalent. The transition from f0 to f14 is colorless due to the absence of electrons, resembling a DD transition. Lanthanide ions, except f0 and f14 types, are paramagnetic when not fully filled. These elements play a crucial role in producing alloy steels for plates and pipes, with Miss Metal containing approximately 95% lanthanide and 5% iron.

  • How does the Lanthanide contraction affect elements?

    The Lanthanide contraction refers to the decrease in size as you move right in the Lanthanide series. This phenomenon occurs due to the poor shielding effect of F orbital electrons, leading to a significant decrease in the sizes of elements in the D block. The presence of 4f sub cells affects the equalization of atomic sizes in elements, making them smaller as you progress through the series. Elements of the 4d series are almost equal in size to those of the 5d series due to the Lanthanide contraction effect. Group number three is not included in this group, and the Lanthanide contraction effect is particularly significant in explaining the changes in atomic sizes.

  • What are the properties of interstitial compounds?

    Interstitial compounds involve small elements like hydrogen, carbon, and nitrogen filling empty spaces in metallic lattices. These compounds have high melting points and are harder than pure metals due to the filled spaces. Borides with trapped boron can be as hard as diamonds due to the hardness of interstitial compounds. Despite their hardness, interstitial compounds retain metallic conductivity and can conduct electricity due to free electrons. They are chemically inert, not reacting with chemicals due to the filled spaces, making them stable and useful in various applications.

  • How do unpaired electrons influence metallic bonding?

    The number of unpaired electrons in metals affects metallic bonding, with more unpaired electrons leading to higher melting and boiling points. Scandium has one unpaired electron, titanium has two, and vanadium has three unpaired electrons, influencing their bonding and physical characteristics. Chromium, with six unpaired electrons, exhibits the highest melting point in the 3D series due to the presence of these unpaired electrons. The energy gap between s and 3d orbitals leads to the evolution of both, resulting in strong interatomic bonding and high melting points in transition elements like chromium.

  • What are the oxidation states of actinides?

    Actinides exhibit a rapid increase in size due to the poor shielding effect of 5f electrons compared to 4f electrons. Actinium commonly shows an oxidation state of +3, similar to lanthanides. Neptunium and plutonium are notable for their various oxidation states, including +3, +4, +5, and +6. Uranium exhibits the highest oxidation state among actinides, reaching up to +6, while neptunium and plutonium show a range of oxidation states up to +6. These elements showcase diverse oxidation states, making them essential in various chemical reactions and applications.

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Summary

00:00

Chemistry: Electron Confinement and Element Series

  • In the 3D series, the electron must be confined within the 3D sub cell.
  • The size of an object decreases when moving from left to right, known as contraction.
  • Cerium plus 4 is an oxidant in chemistry.
  • The chapter of Chemistry D&A Block is being taught on Laksh JE's YouTube channel.
  • The S block elements are on one side, the P block elements on the other, and the D block elements are in between.
  • The F block consists of 28 elements.
  • The D block elements range from Scandium to Zinc, while the F block elements range from Lantham to K's Edge.
  • Lanthanide series consists of 14 elements between Lantham and Half rule.
  • Actinide series includes elements from Actinium to Rutherford's rules.
  • The 3D series includes elements from Scandium to Zinc, the 4D series from Trion to Cadmium, and the 5D series from Lantham to K's Edge.

13:12

Atomic Number Progression and Electronic Configurations

  • The half rule dictates that if the element is 57, Cerium will be 58, and Lutetium will be 71.
  • Following the half rule, the atomic numbers progress as follows: 57, 58, 59, 60, 61, and 71.
  • The rule of 72 involves adding 32 to the atomic number, leading to 72, 73, 74, 75, and eventually 80.
  • Actinium has an atomic number of 89, and Thorium follows with 90.
  • Lawrencium's atomic number is 103, and Rutherford's rule corresponds to 104.
  • The Lanthanide series begins with 57 and ends with 112, with 104 being a significant point.
  • The Lanthanide series is known as the 4f series, while the Actinide series is referred to as the 5f series.
  • Electronic configuration involves placing one electron in the s orbital, except for Palladium, which has zero electrons in the s orbital.
  • In the 3D series, elements have their last electron in the 3d subshell, with the period number indicating the s electrons.
  • Scandium, Titanium, and Vanadium follow specific electronic configurations in the 3D series, with Chromium having an exception with 4s1 configuration.

26:04

Transition Metals Electron Configurations Explained

  • Scandium, Titanium, Vanadium, and Chromium are discussed in terms of their electron configurations.
  • Chromium is noted to be at number four in the series.
  • The value of s is explored when two electrons are present.
  • The electron configuration of 3d 5 is explained.
  • The concept of s1 and its impact on electron configurations is detailed.
  • Copper's electron configuration is discussed, highlighting the role of s1.
  • The electron configuration of Copper is noted to be at number nine.
  • The electron configuration of Zinc is explained, leading to the configuration of 4s 2 3d 10.
  • The concept of inert gas in the 5d series is introduced.
  • The electron configuration of Palladium is discussed, leading to the configuration of 5s 4d.

38:52

Transition and Oxidation States in D-Block Elements

  • Electrons are released from 4s, with two electrons lost in Iron K2 Plus.
  • The transition from 4s to 3d results in the loss of two electrons.
  • The removal of electrons can occur from both 4s and 3d due to similar energy levels.
  • Iron can exhibit various oxidation states, including K + 3 and 3d 5.
  • Scandium maintains a stable + 3 oxidation state, while Zinc remains stable in 4s 2 3d 10.
  • The common oxidation state in the 3D series is + 2, with Manganese capable of reaching + 7.
  • The highest oxidation state in the D block is + 8, seen in I&O.
  • Heavy elements in the D block tend to be stable at higher oxidation states.
  • Scandium is an element that does not show variable oxidation states, always remaining at + 3.
  • Magnetic properties in metals depend on the presence of unpaired electrons, leading to paramagnetic or diamagnetic properties.

52:02

"Color in Coordination Compounds: Electron Transitions"

  • Unpaired electrons with a value of n as one result in a magnetic moment of 1 point something.
  • For unpaired electrons with n values of 2, 3, 4, 5, 4, 3, and 2, the magnetic moment values are 2 point something, 3 point something, 4 point something, 5 point something, 4 point something, 3 point something, and 2 point something, respectively.
  • Coordination compounds in chemistry involve elements from the d-block forming complexion complexes.
  • The color of a compound is determined by the absorption of its complementary color, resulting in the visible color.
  • Example: Titanium h2o 6 3+ is violet in color due to absorbing yellow light.
  • The distribution of ligands in coordination compounds like titanium h2o 6 3+ results in splitting of d orbitals into t2g and eg, making them non-degenerate.
  • Charge transfer spectra explain the color of compounds by the movement of electrons absorbing specific frequencies and transferring between orbitals.
  • D0 systems, where there are no electrons in d orbitals, result in colorless compounds due to the absence of electron transitions.
  • Transition from d1 to d9 orbitals allows for color shows, while d10 systems are colorless due to the impossibility of electron transitions.
  • Charge transfer spectra are responsible for the color of compounds like chromate ions and dichromate ions, where electron transfers create deep yellow and orange colors, respectively.

01:07:19

"Elements, Alloys, and Electron Configurations Explained"

  • Chromium is orange in color, and it's crucial to remember the colors of elements and their regions.
  • Alloys are mixtures of elements, like brass (copper and zinc) and gun metal (copper, zinc, and tin).
  • Stainless steel contains carbon, iron, chromium, and nickel, and it's essential to remember the components to alleviate stress.
  • The F block elements are inner transition elements, with the F block being transition elements.
  • The 4f series in the lanthanide series starts with cerium (atomic number 58) and ends with lattes (atomic number 71).
  • The 5f series starts with thorium (atomic number 90) and ends with lawrencium (atomic number 103).
  • Actinide elements in the 5f series are all radioactive, unlike lanthanide elements.
  • The electronic configuration of lanthanide elements follows specific rules, like the Gado rule, to determine electron placement.
  • Cerium (4f1, 5d1, 6s2) and lattes (4f14, 5d1, 6s2) have distinct electronic configurations in the lanthanide series.
  • Remembering the electron configurations of lanthanide elements, like europium (6s2, 4f7), involves following the Gado rule and understanding electron placement.

01:20:21

Lanthanide Contraction and Atomic Size Changes

  • Lanthanides have a general oxidation state of +3.
  • The electronic configuration for Gado rule 3 is 4f7 and 5d1.
  • When applying Gado's rule, electrons are removed from 6s, 5d, and 4f.
  • The number of unpaired electrons in f7 is crucial for magnetic moment calculations.
  • Lanthanide contraction refers to the decrease in size as you move right in the Lanthanide series.
  • The poor shielding of F orbital electrons leads to Lanthanide contraction.
  • Lanthanide contraction affects the size of elements in the D block.
  • Lanthanide contraction causes the sizes of elements to decrease significantly.
  • Lanthanide contraction explains why the atomic sizes of elements in the D block change.
  • The presence of 4f sub cells affects the equalization of atomic sizes in elements.

01:33:48

Transition in Atomic Radius and Metallic Bonding

  • Elements of the 4d series are almost equal in size to those of the 5d series.
  • Group number three is not included in this group, and the lanthanide contraction effect is significant.
  • The atomic radius decreases with a powerful nucleus due to a high number of protons.
  • Inter-electronic repulsion increases the atomic radius by counteracting the nuclear charge.
  • Moving from scandium to chromium results in a decreasing atomic radius, while copper to zinc shows an increase.
  • The size of the 4d and 5d series elements is equal due to the lanthanide contraction effect.
  • The number of unpaired electrons in metals affects metallic bonding, with more unpaired electrons leading to higher melting and boiling points.
  • Scandium has one unpaired electron, titanium has two, and vanadium has three unpaired electrons.
  • Chromium has a total of six unpaired electrons, while manganese has four, and zinc has zero unpaired electrons.
  • The presence of unpaired electrons influences the properties of metals, affecting their bonding and physical characteristics.

01:47:56

Transition Elements: High Melting Points and Bonding

  • Chromium has the highest melting point due to the presence of unpaired electrons.
  • The energy gap between s and 3d orbitals leads to the evolution of both.
  • Transition elements like chromium have high melting points due to strong interatomic bonding.
  • The melting point of chromium is the highest in the 3D series due to the most unpaired electrons.
  • Tungsten exhibits increased metallic bonding, leading to a high melting point.
  • Tungsten is used in bulb filaments due to its high melting point.
  • Zinc and manganese have stable electronic configurations, affecting metallic bonding.
  • The heat of atomization is higher when metallic bonding is stronger.
  • Vanadium has the highest heat of atomization in the 3D series due to its dense arrangement.
  • Interstitial compounds involve small elements like hydrogen, carbon, and nitrogen filling empty spaces in metallic lattices.

02:04:29

"Interstitial Compounds: Hard, Conductive, and Inert"

  • Hydrogen fills interstitial spaces in titanium, creating interstitial compounds.
  • Small atoms like hydrogen, carbon, nitrogen, or boron get trapped in metal lattice, forming interstitial compounds.
  • Interstitial compounds have high melting points and are harder than pure metals due to filled spaces.
  • Borides with trapped boron can be as hard as diamonds due to the hardness of interstitial compounds.
  • Interstitial compounds retain metallic conductivity and can conduct electricity due to free electrons.
  • Interstitial compounds are chemically inert, not reacting with chemicals due to filled spaces.
  • Interstitial compounds are not reactive but inert, contrary to the original text's claim.
  • Catalysts require a large surface area, variable oxidation states, complexation abilities, and D block metals.
  • Iron is used as a promoter in the Haber process to produce ammonia.
  • Manganese dioxide is used as a catalyst to produce oxygen from potassium chlorate.

02:19:19

Manganese Compounds: Properties and Practical Applications

  • AGBR is known for its light-sensitive properties, making it a photographic material used in the industry.
  • V2O5 is utilized in the production of H2SO4, while titanium tetra chloride or methyl compounds are essential for creating polythene.
  • Mn1 in the +2 oxidation state is paramagnetic, while Mn2+ is diamagnetic due to the presence or absence of unpaired electrons.
  • MnO4 2- is a magnet ion, exhibiting paramagnetic behavior and appearing green in color.
  • Kovalenko compounds, like KMnO4, are non-linear and symmetrical due to the arrangement of oxygen atoms.
  • Pi bonding occurs in Kovalenko compounds through the overlap of oxygen's p orbitals with manganese's d orbitals.
  • The preparation of KMnO4 involves using potassium permanganate as an oxidant to convert Mn2+ to Mn7+.
  • Potassium Poxo Dye Sulfate, or K2S2O8, is a potent oxidant that facilitates the oxidation of manganese salts.
  • The behavior of Mn2+ and Mn1 in the presence of oxidants like potassium permanganate showcases their distinct oxidation states.
  • Understanding the properties and reactions of manganese compounds, such as KMnO4, is crucial for their practical applications.

02:34:40

"Metallurgy, Pyrosite, and KMnO4 Oxidation Reactions"

  • Metallurgy involves cleaning metal to convert it into pure form.
  • Pyrosite is MnO2, used to make KMnO4.
  • KMnO4 is formed by converting Mn4+ to Mn6+ and then to Mn7+.
  • Oxygen from O2 is used to oxidize Mn4+ to Mn6+ in the process.
  • KMnO4 is a strong oxidant, especially in acidic conditions.
  • KMnO4 can be reduced to Mn2+ in acidic conditions.
  • MnO4- can be converted to Mn2+ in neutral conditions.
  • MnO4- can be converted to MnO2 in basic conditions.
  • KMnO4 can be formed by heating MnO2 with K2CO3.
  • KMnO4 can be used as an oxidant in various chemical reactions.

02:49:01

Oxidation State Changes in Chemical Reactions

  • Mn6 is in +2 state, needs to be converted to iodine
  • Iodide ion is converted to iodine, changing from -1 to 0 oxidation state
  • Iron in +2 state turns green, reacts with KMnO4 to form Fe3+
  • Oxalic acid contains carbon in +3 and +4 oxidation states
  • KMnO4 converts oxalic acid to CO2, changing carbon from +3 to +4
  • H2SO3 has sulfur in +4 oxidation state, reacts with H2S to form sulfur at -2 state
  • Thiosulfate converts to sulfate, changing sulfur from +S to +4 oxidation state
  • Nitrite ion with nitrogen at +3 state converts to nitrate ion at +5 state
  • KMnO4 with H+ converts iodide ion to iodate ion
  • Chromite reacts with Na2CO3 and O2 to form Fe2O3 and Na2CO3, increasing sodium's oxidation state and forming iron oxide at +3 state

03:03:28

Chemical Reactions and Oxidation States

  • Cr2O3 reacts with O2 to form CrO3
  • Chromium's oxidation states include +2, +3, and +6
  • Chromium oxide (Cr3) exhibits acidic nature
  • Na2O is the oxide of sodium, showing basic nature
  • Na2Cr4 is formed by combining Na2O and Cr3
  • CO2 is a gas that is released into the environment
  • Converting chromite ore to Na2Cr4 involves adding H+ to form dichromate
  • Potassium dichromate (K2Cr2O7) turns orange when mixed with acid
  • Dye chromate is formed by adding H+ to chromate
  • K2Cr2O7 acts as an oxidant when combined with acid, reducing chromium from +6 to +3

03:18:02

"Copper and Lanthanides: Colorful Chemistry"

  • Copper skull has "2+" written on it, indicating a negative "i" is needed for it to be valuable.
  • Interaction between copper and iodine results in copper 2, which is more stable in water due to hydration energy.
  • Copper 2+ reacts with potassium iodide to form copper iodide, with copper reducing itself to copper plus 1.
  • Cerium's common oxidation state is +3, as it tends to return to this state in reactions.
  • Lanthanides like cerium and ytterbium act as reducing agents among themselves due to their oxidation state tendencies.
  • Cerium ammonium nitrate is used in oxidation processes due to its +4 oxidation state.
  • Lanthanides exhibit color due to the presence of f electrons, making them colorful in solid and aqueous states.
  • DD and FF transitions in lanthanides cause color changes, with DD transitions resulting in brighter colors.
  • Lanthanides like ytterbium have multiple oxidation states, with some being trivalent.
  • The presence of F electrons in lanthanides leads to their colorful nature, while their lack results in colorlessness.

03:32:36

"Transition Metals: Lanthanides and Actinides"

  • Transition from f0 to f14 is colorless due to the absence of electrons, resembling a DD transition.
  • Lanthan 3ps and a3ps result in 0 and 14 electrons respectively in A.
  • Lanthanide ions, except f0 and f14 types, are paramagnetic when not fully filled.
  • Lanthanides are crucial in producing alloy steels for plates and pipes, with Miss Metal containing approximately 95% lanthanide and 5% iron.
  • Magnesium-based lanthanide alloys are used for making bullets and lighter flints.
  • Mixed oxides of lanthanides act as catalysts in petroleum cracking, converting large carbon chains into gaseous forms.
  • Actinides exhibit a rapid increase in size due to the poor shielding effect of 5f electrons compared to 4f electrons.
  • Actinium commonly shows an oxidation state of +3, similar to lanthanides.
  • Neptunium and plutonium are notable for their various oxidation states, including +3, +4, +5, and +6.
  • Uranium exhibits the highest oxidation state among actinides, reaching up to +6, while neptunium and plutonium show a range of oxidation states up to +6.
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