Chapter 17, Problem 56A

Interpretation Introduction

Interpretation: The property that describes heat change at constant pressure is to be named and discussed.

Concept Introduction: Chemical and physical reactions are usually carried in an open atmosphere and thus, all of them occur at constant pressure. Thus, all the heat changes are also measured at constant pressure.

Answer to Problem 56A

The property that describes heat change at constant pressure is enthalpy.

Explanation of Solution

The enthalpy of a system is defined as the total heat content of the system at constant pressure. It is used to account for the heat transfer which happens between the system and the surroundings.