Question #3de10

1 Answer
Jul 7, 2017

Answer:

#"29,900 J"#

Explanation:

In order to be able to answer this question, you need to know the value of the enthalpy of fusion, #DeltaH_"fus"#, of water, which you'll find listed as

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

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

Now, the enthalpy of fusion of a given substance tells you the amount of heat needed in order to convert #"1 g"# of said substance from solid at its melting point to liquid at its melting point.

In this case, you can say that in order to convert #"1 g"# of ice at its normal melting point of #0^@"C"# to #"1 g"# of liquid water at #0^@"C"#, you need to provide it with #"333.55 J"# of heat.

You can thus say that you will need

#89.5 color(red)(cancel(color(black)("g"))) * overbrace("333.55 J"/(1color(red)(cancel(color(black)("g")))))^(color(blue)(=DeltaH_"fus")) = color(darkgreen)(ul(color(black)("29,900 J")))#

in order to melt #"89.5 g"# of ice at its normal melting point.

The answer is rounded to three sig figs, the number of significant figures you have for the mass of ice.