D-F block elements

JEE + NCERT, inorganic chemistry

The d-block of the periodic table contains the elements of groups __________ to __________ .

3 to 12

The f-block of elements in which the _______ and ________ orbitals are progressively filled.

4f, 5f

Elements with partially filled d-orbitals are known as _________ metals.

transition

There are ________ series of transition elements known as ___________ and __________ .

two, lanthanides, actinoids

Zinc, cadmium, and mercury have a filled d-orbital in the ground state and are not considered _______ metals.

transition

The electronic configuration of outer orbtials of d-block elements is generally written as (n-1)d^1-10 ns² except for Pd where it is__________

4d^10

Transition elements display a variety of __________ states.

Oxidation

The 3d series of transition metals starts with __________ (element symbol) and ends with _________ (element symbol)

Sc, Zn

In the d-block, elements are arranged into four rows known as 3d, 4d, 5d, and _______ .

6d

In the d-block, elements are arranged into four rows known as 3d, 4d, 5d, and ________

6d

Greater similarities exist within a ___________ row of transition elements as opposed to a _________ group

horizontal, vertical

The silver aton has filled d-orbitals (_______) in its ground state.

4d^10

The transition metals except Zn, Cd, and Hg are very hard and have low ______________ .

Volatility

The high melting points of transition metals are attributed to the involvement of a greater number of _________ from (n-1)d in addition to the ns electrons in the interatomic metallic bonding.

electrons

The filling of 4f before 5d orbitals results in a series of decreases in atomic radii called ____________ .

lanthanoid contraction

The increase in atomic radius is greater between the 3d and 4d metals than between the _____ and _______ metals because of lanthanide contraction.

4d and 5d

The element with the atomic number 22 is ____________ .

Titanium

The first ionization enthalpy is highest for the element__________ among the first series of transition elements.

Zinc

The transition metals and their compounds are known for their catalytic activity. This activity is ascribed to their ability to adopt multiple _________ and to form complxes.

Oxidation states

The density tends to increase in the 3d series of transition metals from titanium (Z = 22) to __________ (Z = 29)

Copper

The highest density among the transition elements is for the element ____________.

Os (osmium)

The maximum and minimum melting points of first transition and second transition series are of ________ and ________ respectively.

Cr, Cd

Transition elements exhibit higher enthalpies of atomization because of the large number of _________ electrons in their atoms.

unpaired

In the series Sc to Zn, the enthalpy of atomization of _______ is the lowest, i.e 126 kJ mol^-1

Zinc

The increase in ionization enthalpy along a series of transition elements is generally due to any increase in _________ charge

nuclear

The first ionization enthalpy generally __________ , but the magnitude of the increase in the second and third ionization enthalpies for the successive elements is much higher along a series.

increases

The _________ ionization enthalpy of Mn is lower than Cr because of Mn has a 3d^5 4s² configuration and Cr has a 3d^5 4s^1 configuration.

second

The most common oxidation state of transition metals is _________ .

+2

The sum of the first and second ionization enthalpies is required in addition to the enthalpy of atomization to form the ________ ions from the gaseous atoms.

M^+2

The second ionization enthalpy value for Zn is correspondingly_____ as the ionization causes the removal of one 4s electron which results in the formation of stable d^10 configuration.

Low

The third ionization enthalpies are quite high for ________ and _________ due to the stability of their half and fully filled d orbitals.

Mn^+2, Zn^+2

3d-series transition metal which exhibits the largest number of oxidation states is ___________

Mn

In group 6, Mo(VI) and W(VI) are found to be more stable than Cr(VI), thus Cr(VI) in the form of __________ is more stable

Dichromate

Low Oxidation states are found when a complex compound has ligands capable of π-acceptor character in addition to the σ- bonding, for example, in ___________ and _____ .

Ni(CO)4, Fe(CO)5

The 3d transition elements with the greatest number of stable oxidation states exhibit all the oxidation states from +2 to _________

+7

Ionization enthalpy of Fe^+2 is lower than Mn^+2 because Fe^+2 has a _____ configuration.

3d^6

The variability of oxidation states of transition elements is due to the incomplete filling of _________ orbitals in such a way that their oxidation states differ from each other by unity.

d

Titanium (IV) is more stable than titanium (II) or titanium (III) because it has ________ electrons involved in the oxidation state.

No d

Transition metals exhibit higher enthalpies of atomization because of a larger number of _________ electrons

unpaired

The unique behavior of Cu, having a positive E⁰, accounts for its inability to _______ from acids.

Liberate H2

Value of E⁰(M^+2/M) for Mn, Ni and Zn are more negative than expected from the trend. Stability of the half-filled d sub-shell in Mn^+2 and the completely filled d^10 configuration in Zn^+2 are related to their E⁰ values, whereas E⁰ for Ni is related to the highest negative _______________ .

Enthalpy of hydration

The low value E⁰(M^+3/M^+2) for Sc reflects the stability of Sc^+3 which has a _____________ configuration.

Noble gas

The ions Ti^+2, V^+2, and Cr^+2 are strong reducing agents and will liberate ________ from a dilute acid.

Hydrogen

According to the spin only formula, the magnetic moment (µ) is determined by the number of ___________ electrons.

unpaired

A single unpaired electron has a magnetic moment of ___________

1.73 BM

All Cu ^+2 halides are known except the iodide as Cu^+2 oxidizes _____ to _____

I^-, I2

The stability of Cu^+2 (aq) rather than Cu^+ (aq) is due to the much more negative ___________ of Cu^+2 (aq) than Cu^+, which more than compensates for the second ionization enthalpy of Cu.

Hydration enthalpy

The E⁰ (M^+2/M) values for transition metals are related to their ability to form divalent cations, with higher values indicating a ________ tendency to do so.

Lower

The E⁰ value for (V^+2/V) is related to the stability of the ____________ (half filled d level)

v^+2

The ability of fluorine to stabilize the highest oxidation states is exemplified by compounds such as ________ and __________ .

VF5, CrF6

The color observed in the transition element corresponds to the _________ color of the light absrbed.

Complementary

Transition metals such as vanadium oxide in the contact process and nickel in catalytic hydrogenation are known for their __________ properties.

Catalytic

Interstitial compounds formed by transition metals have high melting points and are very hard, sometimes approaching ___________ in hardness.

Diamond

Alloys are blends of metals in which the components are mixed at the atomic level, often resulting in materials that are hards and have ______ melting points.

High

The disproportionation of an oxidation state occurs when it becomes less stable relative to other oxidation states, as in the reaction where manganese(VI) becomes manganese (VII) and manganese (IV) in __________ solution.

Acidic

Oxides and oxoanions of transition metals are typically formed by the reaction of metals with __________ at high temperatures.

Oxygen

Oxides beyond group 7 like those of iron above Fe2O3, are not known because the ___________ oxidation state of these metals exceeds their group number.

Highest

sodium dichromate is more soluble than potassium dichromate and is used in volumetric analysis as a primary standard due to its strong ___________ properties.

Oxidizing

In acidic solution, potassium dichromate represented as Cr2O7^-2 and is known for its oxidizing action that can be represented by the half reaction:

(Cr2O7^-2) + (14H^+) + (6e^-) —> __________ + 7(H2O)

2 Cr^+3

Potassium permanganate is prepared by fusion of MnO2 with an alkali metal hydroxide and an oxidizing agent like __________ . This produces the dark green K2MnO4 which disproportionates in a neutral or acidic solution to give permanganate.

KNO3

The chromate ion is tetrahedral whereas the dichromate ion, Cr2O7²- consists of two tetrahedra sharing one corner with a Cr-O-Cr bond angle of _________

126°

In the presence of sulphuric acid, orange crystals of potassium dichromate can be crystallized from the solution of _________________.

Sodium chromate

When discussing the oxidation states of transition metals, it is noted that manganese exhibits all the oxidation states from +2 to +7, while the lower number of oxidation states are seen in elements like ____________

scandium

The transition metals form a large number of complex compounds. This is due to the comparatively ________ sizes of the metal ions, their _______ ionic charges and the availability of d orbitals for bond formation.

Smaller, high

The transition metals and their compounds are known for their catalytic activity. This activity is ascribed to their ability to adopt multiple ________ and to form complexes.

Oxidation states

The most stable oxidation state of all the lanthanoids is the +3 state which arises from the extra stability of empty, half-filled, or filled ______ sub-shells.

f

The decrease in atomic and ionic radii from lanthanum to lutetium is known as the __________________.

Lanthanoid contraction

Due to the lanthanoid contraction, the radii of the members of the third transition series tend to be very similar to those of the corresponding members of the ________ series.

Second

In the lanthanoids, La(III) and Ln(III) and compounds are predominant, however, occasionally +2 and +4 ions in solution or in solid compounds are also obtained due to the extra stability of _________________ .

• Ln represents any element in the Lanthanoid series

f⁰ and f⁷ configuration

Cerium can exhibit a +4 oxidation state in oxides, like CeO2, because it attains _________ configuration by loosing 2s and 2f electrons.

Noble gas

The earlier members of the lanthanoid series are quite reactive similar to calcium but, with increasing atomic number, they behave more like __________ .

Aluminum

Many trivalent lanthanoid ions are colored both in the solid state and in aqueous solutions due to the presence of ____________ electrons.

f

The single best use of the lanthanoids is for the production of alloy steels for ___________ and pipes.

Plates

A well known alloy is Mischmetal, which is used in Mg-based alloys, C electrodes and consists of about 95% ________ and 5% iron.

Lanthanoid metal

Mixed oxides of lanthanoids are employed as catalysts in petroleum cracking, and some individual Ln oxides are used as __________ in television screens.

Phosphors

Lanthanoids react with _________ to for LnX3 where, X is a halogen.

Halogens

The lanthanoids metals combine with hydrogen when gently heated in the gas. The carbides, Ln3C, Ln2C3, and LnC2 are formed when the metals are heated with ________ . They liberate ___________ from dilute acids.

Carbon, Hydrogen

The reaction of lanthanoids with water at room temperature forms ___________ and liberates Hydrogen gas.

Hydroxides

Oxidation of lanthanoids with sulfur leads to the formation of sulfides ____________.

Ln2S3

Lanthanoids (Ln) also react with nitrogen to form nitrides ___________

LnN

Actinoids are believed to have the electronic configuration of __________ and variable occupancy of the 5f and 6d sub-shells.

7s²

The irregularities in the electronic configurations of actinoids are due to the stabilities of the f°, f⁷, and f^14 occupancies of the 5f orbitals, similar to the stabilities in the ___________ series.

Lanthanoid

The actinide contraction is observed in the actinide series and is greater from element to element than the lanthanoid contraction due to poor shielding by _______.

5f electrons

The oxidation state of actinoids generally starts at +3 and can increase up to +7, as seen in elements like _____ and ________

protactinium (Pa), Neptunium (Np)

Actinoids have ________ which are comparable to the lanthanoids, showing similar properties and gradual variation in properties.

Contraction effects

Actinides, especially when finely divided, are highly reactive and can combine with most non-metals at ______ temperatures.

Moderate

In the photographic industry, the compound relying on the special light - sensitive properties of silver is _______ .

AgBr

The compound TiCl4 with Al(C2H5)3 forms the basis of the _______ catalyst used to manufacture polyethylene.

Ziegler

________ complexes are useful in the polymerization of alkynes and other organic compounds such as benzene.

Ni

The reduction of MnO4⁻ to Mn²⁺ is an example of a redox reaction involving the transfer of _____ electrons

Three

One of the most important uses of d-block elements, specifically iron and steel, is int he construction of ______ and bridges.

Buildings

In comparing the acid-base character of chromium oxides, CrO3 is an acid, while __________ is amphoteric

Cr2O3

Potassium dichromate, K2Cr2O7, is prepared by treating the solution of sodium dichromate with ___________ .

Potassium chloride

The oxidation state of chromium in Cr2O7²⁻ is ____

+6

The purple compound _____ is commercially prepared by the alkaline oxidative fusion of MnO2 followed by the electrolytic oxidation of manganate (VI)

KMnO4

Chromium (VI) compounds, like ________ , are known to be strong oxidizing agents.

Potassium dichromate

The dichromate ion, Cr2O7²⁻, can undergo reduction in acidic solution to form _______ ion.

Cr^+3

In acidic solution, dichromate ions are reduced by iron(II) ions, which are in turn oxidized to ______ ions.

Iron (III)

The preparation of potassium dichromate involves crystallization from a solution of sodium dichromate and potassium chloride, resulting in the formation of _________ crystals.

Orange

A primary standard in volumetric analysis for titrations ___________ is due to its high purity and stable oxidizing power in solutions

Potassium dichromate