Q.

Consider the following ionisation enthalpies of two elements 'A' and 'B' 

Element Ionisation enthalpy kJmol
 1st  2nd3rd
A899 1757 14847
B737 1450 7731

 Which of the following statements is correct?

see full answer

Want to Fund your own JEE / NEET / Foundation preparation ??

Take the SCORE scholarship exam from home and compete for scholarships worth ₹1 crore!*
An Intiative by Sri Chaitanya

a

Both 'A' and 'B' belong to group-1 where 'B' comes below 'A'

b

Both ' A ' and 'B' belong to group-2 where 'A' comes below 'B'

c

Both 'A' and 'B' belong to group-2 where 'B' comes below 'A'

d

Both 'A' and 'B' belong to group-1 where 'A' comes below 'B'

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Both 'A' and 'B' are members of group 2, where 'B' is placed below 'A'.

We notice that the second and third ionisation energies differ significantly. This is typical of metals made of alkaline earth. To create a dipositive ion with a stable electronic structure, they lose 2 valence electrons. It will take a lot of energy to remove the third electron because doing so will disrupt the stable arrangement of the noble gas.

The ionisation energy drops as one descends the group. The needed option is 3 since B's first ionisation energy is lower than A's, hence B comes after A.

Hence, the required option is C)  Both 'A' and 'B' belong to group-2 where 'B' comes below 'A'.

Watch 3-min video & get full concept clarity
AITS_Test_Package
AITS_Test_Package
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon