Guest

For ionic compound A 2+ B 2 2- and C 2 2+ D 2- (a) A 4(S) + B 2(g) → AB 2 ΔH f = -500 Find the lattice energy of AB 2 . (b)Find ΔH f for according D 3(g) + C (S) → C 2 D (s) Given on sublimation of above metal (A 4 ) it dissociates into individual atom. Given: Sublimation energy of A 4 is 1600 ; Sublimation energy of C is 100 Dissociation energy of B 2 IS 200 ; Dissociation energy of D 3 is 90 A (g) → A + (g) ; ΔH = 50 A + (g) → A 2+ (g) ; ΔH=150 B - (g) → B (g) ;ΔH=260 B - (g) → B 2- (g) ;ΔH=250 D (g) → D - (g) ; ΔH=-50 D - (g) → D 2- (g) ; ΔH=100 C + (g) → C (g) ;ΔH=-150 C 2 D (s) → 2C + (g) + D 2- (g) ; ΔH=1000 [ All the values are in kJ/mol] ans: (a)= -780 kJ/mol , (b) = -420 kJ/mol i need explanation...

For ionic compound A2+B22- and C22+D2-


(a) A4(S) + B2(g) → AB2     ΔHf = -500


Find the lattice energy of AB2.


(b)Find ΔHf for according D3(g) + C(S) → C2D(s)


Given on sublimation of above metal (A4) it dissociates into individual atom.


Given: Sublimation energy of A4 is 1600 ; Sublimation energy of C is 100


Dissociation energy of B2 IS 200            ; Dissociation energy of D3 is 90


A(g)  → A+(g) ; ΔH = 50


A+(g) → A2+(g) ; ΔH=150


B-(g) → B(g) ;ΔH=260


B-(g) → B2-(g) ;ΔH=250


D(g) → D-(g) ; ΔH=-50


D-(g) → D2-(g) ; ΔH=100


C+(g) → C(g) ;ΔH=-150


C2D(s) → 2C+(g) + D2-(g) ; ΔH=1000  [All the values are in kJ/mol]


ans: (a)= -780 kJ/mol , (b) = -420 kJ/mol


i need explanation...

Grade:12th Pass

1 Answers

Pankaj
askIITians Faculty 131 Points
9 years ago
Hi student ,
Here is the explaination for calculation.

Accodring to born Habber cycle,
Enthalphy of foramtion of AB2 = Entyalpy sublimation of A + 1stionization enthaly pf A + 2ndionization enthalpy of A+ Enthalpy of atomization of B +2(1st ionization energy of B)+ Lattice energy

Substitution the values and calculating for the value of lattice enthalpy , we get the answer.

Think You Can Provide A Better Answer ?

ASK QUESTION

Get your questions answered by the expert for free