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d and f Block Elements Full Chapter | Class 12 Chemistry Chapter 8 | JEE 2025 Chemistry | Shilpi Mam

Vedantu JEE Made Ejee・2 minutes read

Having a roof over your best friend's house allows for easy access to each other's houses, facilitating playtime, note exchanges, and assignment sharing. The 3D transition series in the periodic table starts from the third period, with the name "3d" indicating the last electron in the 3d sub shell.

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Roof access between friends' houses facilitates playtime and sharing assignments.
3D transition series in the periodic table starts from the third period, with the "3d" name indicating the last electron in the 3d sub shell.
The periodic table chapter is crucial for JE and board exams due to its weightage.
Transition elements show variable oxidation states due to electron transitions between 3d and 4s orbitals.
Lanthanide elements exhibit colored compounds due to unpaired electrons, while fully filled 4f orbitals result in colorless compounds.

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What are transition elements?
Transition elements have incomplete D subshells and variable oxidation states.

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Summary

00:00

Transition Elements: Periodic Table and Properties

Having a roof over your best friend's house allows for easy access to each other's houses, facilitating playtime, note exchanges, and assignment sharing.
The 3D transition series in the periodic table starts from the third period, with the name "3d" indicating the last electron in the 3d sub shell.
The numbers in NCRT tables correspond to periods, with JE questions being crucial.
The session focuses on D&F block, decoding one-liners from NCERT for potential questions.
The periodic table chapter is significant for both JE exams and board exams due to its weightage.
Following the July planner will cover coordination compounds, D&F block, and p block, crucial for chemistry.
Transition elements are those with incomplete D subshells, unpaired electrons, and partially filled orbitals in any oxidation state.
Examples like zinc, cadmium, and mercury are not transition elements due to fully filled D subshells.
Copper, with atomic number 29, is a transition element due to its incomplete D subshell in common oxidation states.
The transition series starts with scandium and progresses through zinc, with tricks to remember the series.

16:39

Transition Series in D Block Elements

Shakti Vikarman and Nikoj are discussing the transition series, starting with the first transition series in the 3d shell.
The first transition series begins from the fourth period, not the third as commonly misunderstood.
The atomic number of scandium is 21, while zinc's is 30.
The second transition series is in the 4d shell, starting from the fifth period.
The third transition series is in the 5d shell, starting from Lanthanum with an atomic number of 57 and ending at Mercury.
There are 14 missing elements between Lanthanum and Hafnium, known as Lanthanides.
The fourth series is radioactive and contains elements with unique properties.
The general electronic configuration for D block elements is n-1d 1-10 ns1-2.
Palladium is an exception in the D block with a unique electronic configuration.
Transition elements show variable oxidation states due to electron relaxation and transition.

32:11

Exceptions in Electron Configurations and Transition Anomalies

36 electrons are filled in the ion up to krypton, then 3 and 38 electrons are added.
Electron configuration should be 4d10 5s2, but sometimes it deviates.
An electron transition occurs from 5s to 4d, causing exceptions in electron configurations.
Rhodium should have an electron configuration of 4d7 5s2, but sometimes an electron from 5s jumps to 4d.
Palladium's electron configuration should be 4d8 5s2, but sometimes both electrons from 5s jump to 4d, resulting in 4d10 5s0.
Exceptions in electron configurations occur in elements like platinum, gold, and lanthanum.
The 4d series has configurations like 43, 46, and 49, with certain exceptions.
The 3d series does not exist, and the 4d series has specific configurations.
Noble gases are used to determine the electron configurations of elements like strontium, cesium, and lead.
The outermost electronic configuration of elements like chromium and manganese can be the same in certain cases.

46:12

"Unpaired Electrons Influence Metal Bonding and Size"

Scandium has 1 unpaired electron in 3d, Titanium has 2, and Chromium has 3, showing an increase in unpaired electrons in metals.
The number of unpaired electrons affects metal-metal bonding strength, with more electrons leading to stronger bonding.
The increase in unpaired electrons causes a decrease in atomic size due to stronger metal-metal bonding.
The trend in 3d elements shows a decrease in atomic size from scandium to chromium, then a slight increase from manganese to nickel.
The effective nuclear charge increases as electrons fill the 3d series, leading to a decrease in unpaired electrons and a smaller atomic size.
Copper and zinc, both with 3d10 configuration, have no unpaired electrons, resulting in weaker metallic bonding and larger atomic size.
The size trend from 3d to 5d elements shows an unexpected similarity in size between 4d and 5d series.
Lanthanoid contraction, caused by poor shielding of 4f electrons, leads to a decrease in atomic size in the 5d series.
Manganese exhibits weak metallic bonding, resulting in a lower melting point compared to other 3d elements.
The melting point trend follows the increase in effective nuclear charge and metallic bonding strength down the group, with exceptions like zinc, cadmium, and mercury having higher melting points despite their configurations.

01:02:12

"Transition metals: Mass, volume, and ionization energy"

Comparing mass and volume to understand density
Density increases with mass, not size or volume
Special case of transition metals in oxidation states
Transition metals' electron transitions between 3d and 4s
Exchange energy in transition metals for stability
Ionization energy variations in 3D series
Zinc has the highest ionization energy in the 3D series
Impact of electron exchange on ionization energy
Comparison of ionization energy in different transition metals
Understanding ionization energy trends and exchange energy in transition metals

01:17:39

Transition Elements: Variable Oxidation States and Trends

Scandium has an atomic number of 21 and a configuration of 4s2 3d1, showing a +3 oxidation state.
Zinc has a configuration of 3d10 4s2, with a full d orbital, leading to a +2 oxidation state.
Transition elements in the 3d series can exhibit variable oxidation states.
Copper can display +1 and +2 oxidation states, while Titanium can reach up to +4.
Vanadium can show oxidation states of +2, +3, +4, and +5, and Chromium can exhibit +2, +3, +4, and +5 states.
Iron can display +2, +3, +4, and +6 oxidation states, and Cobalt can show +2, +3, and +4 states.
Scandium typically shows a +3 oxidation state, while Zinc does not exhibit variable oxidation states.
Standard electrode potential involves reduction potential and oxidation potential, with values indicating tendencies for oxidation or reduction.
The trend of effective nuclear charge increasing leads to higher ionization energy and decreased reactivity under water.
Manganese is an exception, stable in the +2 oxidation state due to low ionization energy and a half-filled 3d orbital.

01:32:34

Transition Metals: Electrons, Catalysts, and Colors

Manganese 2+ has 35 electrons and is half-filled.
Manganese is not in 2ps.
Transition to Libre Hydrogen Gas is simple.
Magnetic Behavior Coordination Compound Ship Arrived.
Electrons rotate on their axis and revolve around the nucleus in orbit.
The spin magnetic moment expression is the square root of n(n + 2) Bohr.
The number of unpaired electrons is crucial in determining experimental momentum.
Transition metals can be used as catalysts due to variable oxidation states and active surfaces.
Catalysts reduce activation energy, increasing the rate of reaction.
Transition metal ions exhibit color due to DD transition and charge transfer phenomenon.

01:47:10

"Coordination Chemistry and Metal Properties"

Electron captures nucleus, requires vacant orbitals for coordination
Vacant d orbital n -1 d electron acceptor needed for coordination
Donor species with loan pair required for coordination
Transition Metal Ions can change oxidation state, enhancing catalytic properties
Iron +3 catalyzes sulfate reaction with iodide, due to Fe3+ properties
Interstitial compounds form in crystal lattice structures with small atoms trapped
Non-stoichiometric compounds have unique properties, like high melting points
Interstitial compounds maintain metallic conductivity but reduce reactivity
Intermetallic alloys form through intermixing metals with similar sizes
Halides in 3D series exhibit various oxidation states, affecting reactivity and properties

02:03:04

"Chemical Reactions Form Potassium Dichromate"

Sodium oxide and chromium oxide react together to form cro4.
Iron oxide, in the form of fe2o3, remains as a precipitate and is insoluble.
The reaction involves sodium carbonate and sodium oxide in a fused state.
Filtration is required to separate the precipitate from the soluble na2cro4.
Potassium dichromate is made from na2cro4 by adding an acidic medium.
Chromate ion is stable in a basic medium, while dichromate ion is stable in an acidic medium.
The chromate ion is orange, while the dichromate ion is yellow in color.
The structure of chromate and dichromate ions involves resonance and equivalent bond lengths.
Tetrahedral geometry and d pi p pi bonds are present in dichromate.
Potassium dichromate is a strong oxidant, changing the oxidation state of chromium.

02:18:49

Potassium Permanganate: Preparation, Properties, and Applications

The correct answer is option A B D, which indicates tetrahedral geometry and chromate formation.
Potassium permanganate is discussed, with the preparation involving pyrolysis with potassium hydroxide in the presence of oxygen.
The source of oxygen for the reaction can be any compound that releases oxygen when heated.
The reaction with potassium hydroxide results in the formation of potassium manganate, which is green in color.
The oxidation state of manganese in potassium permanganate is highlighted, showing its tendency to reach +7.
Dysprosium is mentioned in the context of oxidation and reduction, with manganese being oxidized to +6 and reduced to +4 to form KMnO4.
The preparation of potassium permanganate in the laboratory involves the reaction of potassium permanganate with manganese dioxide and sulfuric acid.
Heating KMnO4 leads to the reduction of manganese dioxide, showcasing the redox reaction involved.
The color of potassium permanganate is attributed to the charge transfer transitions, with the ion exhibiting a tetrahedral structure.
The behavior of KMnO4 as an oxidant is explained, with its ability to reduce other substances due to its oxidation state and N factor in different mediums.

02:34:53

Electron Filling and Lanthanide Elements Characteristics

Electron filling sequence follows the off bow rule, with electrons filling from low to high energy orbitals.
Across a period, the energy sequence for electron filling is ns2, with an example of 54 electrons filling 6s2.
F block elements' general configuration includes ns2, n-2f 0 to 14, and n-0 to 1 in 1d, with exceptions like Thorium.
Lanthanide contraction leads to a decrease in atomic and ionic radii due to poor shielding of 4f orbitals.
The effect of lanthanide contraction results in a decrease in both atomic and ionic radii.
Lanthanide elements are silvery soft metals known as rare earth metals, with reactivity higher than hydrogen.
Rare earth metals exhibit colored compounds due to unpaired electrons leading to F-F transitions.
Unpaired electrons in lanthanide elements cause absorption and emission of energy, resulting in colored compounds.
Lanthanide elements commonly exhibit an oxidation state of +3, representing unity.
Fully filled 4f orbitals in lanthanide elements result in colorless compounds due to the absence of unpaired electrons.

02:50:07

Oxidation States in Elements: Stability and Reactivity

Stable oxidation states include +3, but some elements can also show +4 and +2.
Understanding oxidation states is crucial for JE questions.
Elements in +4 oxidation state may prefer to go to +3 for stability.
Elements in +3 oxidation state may gain electrons and act as oxidants.
Lanthanides in +2 oxidation state may prefer to go to +3.
Lanthanides react with water to form hydroxides and hydrogen.
Lanthanides can form hydrides that react with water to release hydrogen.
Lanthanides are used in making alloys like mish metal for bullets.
Stability of oxidation states increases down the group in D block elements.
Actinides show a variety of oxidation states due to small energy gaps.

03:05:13

Enhancing Academic Understanding Through Visual Solutions

Emphasizes the importance of clearing doubts and understanding concepts thoroughly in academic topics, suggesting the use of photo and video solutions for clarity and detailed explanations. Provides an example of electron extraction from 4f and the significance of practicing and solving additional questions for better comprehension.
Encourages active participation in academic sessions, particularly in the study of Lanthanoids and the importance of confining, while reminding viewers to download session PDFs for reference and to engage in regular practice for effective learning in organic chemistry.

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