Chapter 7, Problem 108AE

Interpretation Introduction

Interpretation: The standard heat of formation of  ${\text{ICI}}_{\left(\text{g}\right)}$ should be calculated.

Concept Introduction:

Standard Enthalpy of Formation:

• The one mole of the product is formed by its standard state via the reaction of its elements in standard state at standard conditions.
• The at constant pressure the standard enthalpy of formation is equal to standard heat of formation.

Hess's Law:

•  Hess's Law is saying that if you convert reactants to products the overall enthalpy change will be exactly the same whether you do it in one or multiple steps.

            Formula:

                            $\text{ΔH}\left(\text{total}\right)\text{= }{\displaystyle \sum \text{ΔH}}\left(\text{number of steps}\right)\mathrm{......}\text{(1)}$

Rules:

• The sign of ΔH reversed when the reaction is reversed.
• The quantities of reactants and products is directly proportional to the magnitude of ΔH in a reaction. If the coefficients in a balanced reaction are multiplied by an integer, the value of ΔH is multiplied by the same integer.