[plat_num]

I understand that dU= q - w and therefore we can state that as Q=dU+ w

Since dU= q - w, substituted that into Q=du+w we get Q= q - w + w. So basically H = q.

What I can't comprehend is where constant pressure plays a role!  Why is enthalpy the heat associated with a process carried out at constant pressure, when it seems that constant pressure or not H=q?  I've read numerous articles and texts regarding Enthalpy but I always walk away with the same questions in my head.  Thanks for your time guys.

[enahs]

Are you familiar with calculus?
It is easy enough to show with calculus, and it comes from the calculus why we use q_p as well.

[plat_num]

Well I understand basic calculus, but how come for internal energy, work, pressure, etc you don't need to know calculus?  What is it about enthalpy that makes it elusive to comprehend?

[Hunt]

You proved that q =q , which means nothing. First begin by defining the enthalpy , which is : H = U + pV .
It becomes apparent then that the change in enthalpy equals the heat transfered at const pressure.