The melting point of a substance is the temperature at which it changes from a solid to a liquid. In order to determine the melting point of NaCl (sodium chloride), we need to consider the heat required for melting and the change in entropy.

Heat required for melting (delta H):
The heat required for melting, or the enthalpy change (delta H), can be calculated using the formula:
delta H = q/m
where q is the heat absorbed or released during the phase change and m is the amount of substance in moles.

Given that the heat required for melting NaCl is 7.26 Kcal/mol, we can convert it to Joules:
7.26 Kcal/mol * 4.18 J/cal = 30.32 KJ/mol

Change in entropy (delta S):
The change in entropy, or the increase in disorder, during the phase change can be calculated using the formula:
delta S = q/T
where q is the heat absorbed or released during the phase change and T is the temperature in Kelvin.

Given that the change in entropy for NaCl melting is 6.73 cal/(mol*K), we can convert it to Joules:
6.73 cal/(mol*K) * 4.18 J/cal = 28.06 J/(mol*K)

Calculating the melting point:
To determine the melting point of NaCl, we can use the equation:
delta G = delta H - T * delta S

At the melting point, the change in Gibbs free energy (delta G) is zero. Therefore, we can rearrange the equation to solve for the temperature (T):
delta G = 0
0 = delta H - T * delta S
T = delta H / delta S

Substituting the values we have:
T = 30.32 KJ/mol / 28.06 J/(mol*K)
T = 1083.4 K

The melting point of NaCl is approximately 1083.4 Kelvin.

By considering the heat required for melting and the change in entropy, we can determine the temperature at which NaCl changes from a solid to a liquid. The heat required for melting NaCl is 7.26 Kcal/mol, and the change in entropy is 6.73 cal/(mol*K). Using these values, we can calculate the melting point to be approximately 1083.4 Kelvin.