What amount of heat is required to completely melt a 29.95-gram sample of #H_2O(s)# at 0° C?
When a sample of water melts from ice at
As you know, phase changes take place at constant temperature. All the heat added to the sample goes into disrupting the strong hydrogen bonds that keep the water molecules locked in place in the solid state.
This means that you can't use water or ice's specific heat, since the heat added does not change the sample's temperature.
Instead, you will use water's enthalpy of fusion,
Water's enthalpy of fusion is approximately equal to
#DeltaH_f = "334 J/g"#
This tells you that in order to convert
In your case, the sample is said to have a mass of
#29.95 color(red)(cancel(color(black)("g"))) * "334 J"/(1color(red)(cancel(color(black)("g")))) = "10,003.3 J"#
Rounded to four sig figs, the answer will be