# Question #27012

##### 1 Answer

#### Explanation:

You need to know the value of water's **enthalpy of fusion**,

#DeltaH_"fus" = "333.55 J g"^(-1)#

https://en.wikipedia.org/wiki/Enthalpy_of_fusion

The enthalpy of fusion tells you the amount of heat needed to convert

For water, you need

This implies that

#45.0 color(red)(cancel(color(black)("g"))) * "333.55 J"/(1color(red)(cancel(color(black)("g")))) = "15009.75 J"#

Expressed in *kilojoules* and rounded to three **sig figs**, the answer will be

#color(darkgreen)(ul(color(black)("heat needed" = 1.50 * 10^4color(white)(.)"kJ")))#