**Answer : The enthalpy change or heat required is, 139.28775 KJ**

**Solution :**

**The conversions involved in this process are :**

**Now we have to calculate the enthalpy change.**

where,

= enthalpy change or heat required = ?

m = mass of water = 45 g

= specific heat of solid water =

= specific heat of liquid water =

= specific heat of liquid water =

n = number of moles of water =

= enthalpy change for fusion = 6.01 KJ/mole = 6010 J/mole

= enthalpy change for vaporization = 40.67 KJ/mole = 40670 J/mole

**Now put all the given values in the above expression, we get**

(1 KJ = 1000 J)

**Therefore, the enthalpy change is, 139.28775 KJ**