Find the heat that of sublimation of sodium metal from the following data. Ionisation enegry of sodium `= 502.1`, bond enegry of chlorine `=242.8`, heat of formation of `NaCI = - 411.1`, lattice energy of `NaCI =- 778.0`, and electorn affinity of chlorine is `-365.3`. All units are in `kJ mol^(-1)`.

Explanation

To find the heat of sublimation of sodium metal, we can use the Born-Haber cycle and Hess's law. The enthalpy of formation of NaCl can be expressed in terms of various energies involved in the process. Here’s a step-by-step solution:

### Step 1: Write the Born-Haber cycle equation
The enthalpy of formation of NaCl can be expressed as:
\[ \Delta H_f = \Delta H_{\text{sublimation}} + \Delta H_{\text{ionization}} + \Delta H_{\text{bond}} + \Delta H_{\text{electron affinity}} + \Delta H_{\text{lattice}} \]

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