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प्रश्न
Define ionisation enthalpy. Discuss the factors affecting ionisation enthalpy of the elements and its trends in the periodic table.
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उत्तर
The amount of energy required to remove an electron from the outermost shell of an isolated gaseous atom in its ground state is said to be ionisation enthalpy.
The factors that affect ionization enthalpy of the elements are as follows:
a. Effective nuclear charge with its increase the ionization enthalpy also increases
b. Atomic size with its increase the ionization enthalpy decreases
c. The \[\ce{e- - e-}\] repulsion with its increase the ionization enthalpy decreases
d. Whenever there exists half-filled or completely filled orbital than it lead to increase the ionization enthalpy because it leads to give extra stability to the atom due to symmetry
The ionization enthalpy decreases down the group and increases across the period.
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संबंधित प्रश्न
Among the second period elements the actual ionization enthalpies are in the
order Li < B < Be < C < O < N < F < Ne.
Explain why O has lower ΔiH than N and F?
How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?
What are the various factors due to which the ionization enthalpy of the main group elements tends to decrease down a group?
The first ionization enthalpy values (in kJmol–1) of group 13 elements are:-
| B | Al | Ga | In | Tl |
| 801 | 577 | 579 | 558 | 589 |
How would you explain this deviation from the general trend?
Would you expect the first ionization enthalpies for two isotopes of the same element to be the same or different? Justify your answer.
Which one of the following statements is incorrect in relation to ionization enthalpy?
Among the elements \[\ce{B, Al, C}\] and \[\ce{Si}\], which element has the highest first ionisation enthalpy?
Explain the deviation in ionisation enthalpy of some elements from the general trend by using the given figure.
Explain the following:
Ionisation enthalpy decrease in a group from top to bottom?
Discuss and compare the trend in ionisation enthalpy of the elements of group1 with those of group17 elements.
Consider the elements Mg, Al, S, P and Si, the correct increasing order of their first ionization enthalpy is ______.
For the gaseous reaction, \[\ce{K_{(g)} + F_{(g)} -> K^+_{ (g)} + F^-_{ (g)}}\], ΔH was calculated to be 19 kcal/mol under conditions where the cations and anions were prevented by electrostatic separation from combining with each other. The ionisation energy of K is 4.3 eV. The electron affinity of F is ______. (in eV)
`"A"_0/2` atoms of X(g) are converted into X+(g) by absorbing energy E1. `"A"_0/2` ions of X+(g) are converted into X−(g) with release of energy E2. Hence ionization energy and electron affinity of X(g) are ______.
The decreasing order of the second ionization potential of K, Ca and Ba is ______.
Which of the following atoms has the highest first ionization energy?
Arrange the following elements in increasing order of first ionization enthalpy:
Li, Be, B, C, N
Choose the correct answer from the options given below:
