JEE Main 2022 · 28 Jul · Shift 1 · Chemistry Q65

ChemistrySingle correct+4 / -1Question 65 of 90

In which of the following pairs, electron gain enthalpies of constituent elements are nearly the same or identical ?

(A) Rb and Cs
(B) Na and K
(C) Ar and Kr
(D) I and At

Choose the correct answer from the options given below :

(A) and (B) only

(B) and (C) only

(A) and (C) only

Answer and worked solution

Official answer: C

Rb and Cs are nearly equal (about −47 and −46 kJ mol $^{-1}$ ). Ar and Kr are identical estimates (+96 kJ mol $^{-1}$ ).

(C)

Topics:Electron gain enthalpy

JEE Main 2022 · 28 Jul · Shift 1, Chemistry question 65