Given below are two statements: Statement I: The decrease in first ionization enthalpy from B to Al is much…

Given below are two statements:

Statement I: The decrease in first ionization enthalpy from B to Al is much larger than that from Al to Ga.

Statement II: The d orbitals in Ga are completely filled.

In the light of the above statements, choose the most appropriate answer from the options given below

  1. Statement I is incorrect but statement II is correct.
  2. Both the statements I and II are correct
  3. Statement I is correct but statement II is incorrect
  4. Both the statements I and II are incorrect

Solution

First ionization enthalpy (IE1) of B, Al, Ga are 801, 577 and 579 kJ/mol respectively. 

As decrease in first ionization enthalpy is much larger from B to Al. ∆IE1 of B and Al is greater than ∆IE1 of Al and Ga. So, the statement I is correct.

This is due to completely filled d-orbitals in Ga and d-electron have low screening effect to compensate the increase in nuclear charge. So, The statement II is also correct.

Hence, the correct option is B.

 

Asked in: JEE Main 2023 (29 Jan Shift 2)

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