Question

If a solid has a heat of fusion of 17.02 kJ/mol and an entropy of fusion of 38.98 J/mol- K, what is the melting point in °C) of this pure solid? Type your answer rounded to 1 decimal place without units (i.e. NN.N).

Answer 1

Step-by-step explanation:

Melting point is defined as the point at which a solid substance starts to change into liquid state.

Whereas entropy is the degree of randomness of molecules present in a substance.

Heat of fusion is defined as the amount of heat energy necessary to melt a solid substance at its melting point.

Relation between entropy and heat of fusion is as follows.

`\Delta S = (\Delta H)/(T)`

where,
`\Delta S` = 38.98 J/mol K

`\Delta H` = 17.02 kJ/mol

=
`17.02 kJ/mol * (1000 J)/(1 kJ)`

= 17020 J/mol

Therefore, calculate the melting point as follows.

`\Delta S = (\Delta H)/(T)`

38.98 J/mol K =
`(17020 J/mol)/(T)`

T = 436.63 K

Change the temperature into degree celsius as follows.

`(436.63 - 273)^(o)C`

=
`163.63^(o)C`

Thus, we can conclude that the melting point in
`^(o)C` is
`163.63^(o)C`.