What is the thermal energy in #"kJ"# required to melt #"10.234 mols"# of ice?

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Answer 1 · 2017-10-18T01:09:38

#q = "61.6 kJ"#

Well, you should supply the data that I'm supplying you:

#DeltaH_"fus" = "6.02 kJ/mol ice"#
#DeltaH_"vap" = "40.67 kJ/mol water"#

At constant pressure, the heat flow #q# is equal to the change in enthalpy #DeltaH#. Thus:

#q = DeltaH#, if both are in #"kJ"#...

But since I have given you values in #"kJ/mol"#, you must convert them to #"kJ"#:

#q = nDeltabarH#

where #DeltabarH# is in #"kJ/mol"# and #q# is in #"kJ"#.

Therefore, the thermal energy required must be:

#color(blue)(q) = 10.234 cancel"mols ice" xx "6.02 kJ/"cancel"mol" = color(blue)("61.6 kJ")#

Why did I not use #"40.67 kJ/mol"#?