# What is the minimum amount of heat required to completely melt 20.0 grams of ice at its melting point? A. 20.0J B. 83.6J C. 6680J D. 45,200J How do you solve

##### 1 Answer

The answer is **(C)**

#### Explanation:

In order to be able to answer this question, you need to know the value of water's *enthalpy of fusion*,

As you know, a substance's enthalpy of fusion tells you how much heat is **needed** to melt **ice** at **liquid** at

Simply put, a substance's enthalpy of fusion tells you how much heat is required to get *solid* *liquid* phase change.

Water's enthalpy of fusion is approximately equal to

#DeltaH_f = 334"J"/"g"#

http://www.engineeringtoolbox.com/latent-heat-melting-solids-d_96.html

This tells you that in order to melt

In your case, you have **times more heat** than you would need for

Therefore, you can say that

#20.0 color(red)(cancel(color(black)("g ice"))) * "334 J"/(1color(red)(cancel(color(black)("g ice")))) = "6680 J"#

are needed to melt

Therefore, **(C)**