NEETChemistryp Block Elements (Group 15, 16, 17 & 18)
Match List-I with List-II regarding the properties of Group 17 elements and their compounds: (A) Acidic strength of HX (I) Cl₂ Br₂ F₂ I₂ (B) Bond dissociation enthalpy of X₂ (II) Cl F Br I (C) Negative electron gain enthalpy of X (III) HI HBr HCl HF (D) Oxidising power of X₂ (IV) F₂ Cl₂ Br₂ I₂ Choose the correct answer from the options given below:
Options
- A(A)-(III), (B)-(I), (C)-(II), (D)-(IV)
- B(A)-(IV), (B)-(I), (C)-(II), (D)-(III)
- C(A)-(III), (B)-(IV), (C)-(II), (D)-(I)
- D(A)-(III), (B)-(I), (C)-(IV), (D)-(II)
Correct answer
A. (A)-(III), (B)-(I), (C)-(II), (D)-(IV)
Step-by-step solution
(A) Acidic strength of HX : The acidic strength increases down the group as the size of the halogen atom increases, which decreases the H-X bond dissociation enthalpy. Order: HI HBr HCl HF . (B) Bond dissociation enthalpy of X₂ : Fluorine has an anomalously low bond dissociation enthalpy due to strong interelectronic repulsions between the lone pairs on the small fluorine atoms. Order: Cl₂ Br₂ F₂ I₂ . (C) Negative electron gain enthalpy of X : Chlorine has a more negative electron gain enthalpy than fluorine becaus