Question

The lattice energy of $NaCl$ is $788kJmo{l}^{-1}$. This means that $788kJ$ of energy is required:

• A. to separate one mole of solid $NaCl$ into one mole of $Na\left(g\right)$ and one mole of $Cl\left(g\right)$ to infinite distance
• B. to separate one mole of solid $NaCl$ into one mole of $N{a}^{+}\left(g\right)$ and one mole of $C{l}^{-}\left(g\right)$ to infinite distance
• C. to convert one mole of solid $NaCl$ into one mole of gaseous $NaCl$
• D. to convert one mole of gaseous $NaCl$ into one mole of solid $NaCl$
• E. to separate one mole of gaseous $NaCl$ into one mole of $N{a}^{+}\left(g\right)$ and one mole of $C{l}^{-}\left(g\right)$ to infinite distance

Answer 1

Answer: (B)

to separate one mole of solid $NaCl$ into one mole of $N{a}^{+}\left(g\right)$ and one mole of $C{l}^{-}\left(g\right)$ to infinite distance

Lattice energy is that amount of energy which is required to separate one mole of a solid into its constituents gaseous ions at infinite distances.

Since the lattice energy of $NaCl$ is $788kJmo{l}^{-1}$, it means that $788kJ$ of energy is required to separate one mole of solid $NaCl$ into one mole of $N{a}^{+}\left(g\right)$ and one mole of $C{l}^{-}\left(g\right)$ to infinite distance.

Hence, option B is correct.