physical or phase change

[Delilah Naranjo dis 3j]

I have a question how does sublimation equal

delta H of sub= delta H of fus + delta H of vap????

[sophianguyen_1N]

Sublimation is the conversion of a solid directly to a gas. Because enthalpy is a state function, you could also look as this process as a solid becoming a liquid first, and then a gas. The enthalpy value for that process would be the same as the solid substance becoming a gas immediately. Therefore, delta H_sub is also equal to the addition of delta H_fus (solid to liquid) and delta H_vap (liquid to gas).