Q16 / 160 · TS EAMCET 2006 · Chemistry

$A B$ is an ionic solid. The ionic radii of $A^{+}$and $B^{-}$ are respectively $r_c$ and $r_a$. Lattice energy of $A B$ is proportional to :

  • A
    $\frac{r_c}{r_a}$
  • B
    $\left(r_c+r_a\right)$
  • C
    $\frac{r_a}{r_c}$
  • Correct answer
    D
    $\frac{1}{\left(r_c+r_a\right)}$

Solution

The lattice becomes stronger (i.e., the lattice energy $U$ becomes more negative), as $r$ the inter ionic distance decreases. $U$ is proportional to $\frac{1}{r}$ or $U \propto \frac{1}{\left(r_c+r_a\right)}$

Hence, the correct answer is option: 'D'.

Relevant Questions