AP EAMCET202120 Aug 2021Evening ShiftChemistryClassification of Elements and Periodicity in PropertiesActual
The first ionization enthalpies of Mg and Al can be expected to be
Options
- AIE 1 ( Mg ) = 577 . 5   kJ · mol - 1 , IE 1 ( A l ) = 577 . 5   kJ . mol - 1
- BIE 1 ( Mg ) = 577 . 5   kJ . mol - 1 , IE 1 ( A l ) = 737 . 7   kJ . mol - 1
- CIE 1 ( Mg ) = 737 . 7   kJ . mol - 1 , IE 1 ( A l ) = 737 . 7   kJ . mol - 1
- DIE 1 ( Mg ) = 737 . 7   kJ . mol - 1 , IE 1 ( Al ) = 577 . 5   kJ . mol - 1
Correct answer
D. IE 1 ( Mg ) = 737 . 7   kJ . mol - 1 , IE 1 ( Al ) = 577 . 5   kJ . mol - 1
Step-by-step solution
Magnesium has the atomic number of 12 . It has the electronic configuration of Ne 3 s 2 . It has the fully filled orbitals. So, it has the high ionisation energy. The atomic number of the aluminium is 13 . It has the electronic configuration of Ne 3 s 2 3 p 1 . It has the low value of the first ionisation energy. So, the first ionisation energy of magnesium is higher than the aluminium because magnesium has the fully filled orbital. Hence, The first ionization enthalpies of Mg and Al can be expected to be IE 1 ( Mg