Chapter 8, Problem 8.73SP

Interpretation Introduction

Interpretation:

The reason for elements always having $\Delta H_f^{°}=0$ has to be explained

Concept Introduction:

The standard state of an element is defined as the stable phase of the element exists under standard conditions that are – $25°C$ temperature and $1atm$ pressure.

Standard heat of formation of a compound is termed as quantity of heat absorbed or evolved at $25°C$ temperature and $1atm$ pressure when one mole of a compound is formed form its constituent elements in pure form under the same reaction conditions at $25°C$ temperature and $1atm$ pressure.