Question

If $A\left(s\right)\to A^{+}\left(g\right)+e$...................600 kJ/mol
$B_2\left(g\right)+e\to B^{-}\left(g\right)$......................260kJ/mol
$A\left(s\right)+B_2\left(g\right)\to A{B}_{(}s)$...............-550kJ/mol
The lattice energy of $A{B}_{(}s)$ Will be:

• A. $-160$
• B. $-890$
• C. $-420$
• D. $+360$

Answer 1

The correct option is D $+360$

$A\left(1\right)\to A^{+}+e^{-}$ $600kJ\left(E_1\right)$

$B_2+e^{-}\to 2B^{-}$ $260kJ\left(E_1\right)$

$2A+B_2\to 2AB$ $-550kJ\left(E_1\right)$

Lattice energy $=2E_1+E_2+2E_3$

LE $=2\left(600\right)+260+2(-550)$

LE $=100+260$

LE $=360KJ/Mol$