[offlinedoctor]

Hi everyone,

I'm having trouble understanding the difference between q, in the equation, ΔE= q+w, and ΔH, don't they both refer to the amount of heat released per mole?

While for, work, why is it that we always multiply it by 101.3 to convert work into joules, and not just have it become a part of works equation?

Thank You. 

[Sunil Simha]

q refers to the heat transfer in the system for a general thermodynamic process. ΔH on the other hand refers to the heat transfer at constant pressure i.e. you are maintaining the pressure of the system at a constant level (like when you perform the process in an open vessel. The pressure of the system is the atmospheric pressure).

I'm not sure why you are multiplying work by 101.3 but I think you are finding the work initially using liter-atmosphere as the units. To convert it to SI units (Pa-m³) you need to multiply it by 101.3