What is the equation for the calculation of heat of fusion?
The enthalpy of fusion,
The only "equation" that utilizes
#q_"fus" = pmnDeltaH_"fus"#
#q_"fus"#is the heat flow at constant atmospheric pressure, that pertains to either melting or freezing. Here it is in units of #"kJ"#.
#n#is the mols of liquid being freezed, or the mols of solid being melted.
#DeltaH_"fus"#is the enthalpy of fusion, and is a positive quantity usually reported in #"kJ/mol"#.
#q_"fus" -= q_"melt" = nDeltaH_"fus"#
If one wishes to freeze a liquid...
#q_"fus" -= q_"freeze" = -nDeltaH_"fus"#
And this is because the object is the system... so
- heat flowing in to melt it must be given a positive sign, for the system gains heat to melt.
- heat flowing out to freeze it must be given a negative sign, for the system loses heat to freeze.