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How would you account for the irregular ...

How would you account for the irregular of ionisation enthalpies (first) in the first series of the transition elements?

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For first five elements , the effective nuclear charge predominates over shielding effect and thus ionisation energy increase . In next Five element , Shielding effect increase more rapidly due to dense packing of electron in d-orbitals (pairing take place ) and the effective nuclear charge and shield effect counter balance each other to show a net result constant ot irregular but closer trend in ionisation energy values.
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How would you account for the irregular variation of ionisation enthalpies (first and second) in the first series of the transition elements?

How would you account for the irregular variation of ionization enthalpies ( first and second) in first series of the transition elements ?

Knowledge Check

  • The first transition element is

    A
    Cr
    B
    Sc
    C
    Zn
    D
    Cu

  • The first ionisation energies of the elements of the transition series.

    A
    Increases as the atomic number increases
    B
    Decreases as the atomic number increases
    C
    Do not show any change as the addition of electrons takes place in the inner `(n-1)` d-orbitals.
    D
    None of these

  • The CORRECT order of first ionisation enthalpy is :

    A
    `Mg lt S lt Al lt P `
    B
    `Mg lt Al lt S lt P`
    C
    `Al lt Mg lt S lt P`
    D
    `Mg lt Al lt P lt S`

    • Similar Questions

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    (i) Which of the first row transition metal exhibit +7 oxidation state? (ii) How would you account for the irregular variation of 1st and 2nd ionisation enthalpies in the 1st series of transition elements ? (iii) What are interstitial compounds ? (iv) Give two uses of potassium permanganate.

    Assing a reason for each of the following observation : (i) The transition metals (with the exception of Zn, Cd and Hg) are hard and have high melting and boiling points (ii) The ionisation enthalpies (first and second) in the first series of the transition elements are found to vary irregularly

    How would you account for the following? (i) The atomic radii of the metals of the third (5d) series of transition elements are virtually the same as those of the corresponding member of the second (4d) serie (ii) Because oxygen and fluorine are highly electronegative elements and small in size.

    (a) Write balanced equations to represent what happens when (i) Cu^(2+) is treated with KI. (ii) Acidified potassium dichromate solution is reacted with iron (II) solution (ionic equation). (b) (i) The figure given below illustrates the first ionisation enthalpies of first, second and third series of transition elements. Answer the questions that follow : Which series amongst the first, second and third series of transition elements have the highest first ionisation enthalpy and why ? (ii) Separation of lanthanoid elements is difficult. Explain. (iii) Sm^(2+), Eu^(2+) and Yb^(2+) ions in solution are good reducing agents but an aqueous solution of Ce^(4+) is a good oxidising agent. Why?

    Why is enthalpy of atomisation is the lowest for Zn in 3d series of transition elements ?

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