Chapter 5, Problem 66QP

Interpretation Introduction

Interpretation:

The heat of combustion of the given reactions at ${25}^{\text{o}}\text{C}$ is to be calculated.

Concept introduction:

The enthalpy of a reaction that takes place under standard conditions is known as the standard enthalpy of the reaction.

The standard enthalpy of a reaction can be calculated as

$\Delta H{°}_{\text{rxn}}=\left[c\Delta H{°}_f\left(C\right)+d\Delta H{°}_f\left(D\right)\right]-\left[a\Delta H{°}_f\left(A\right)+b\Delta H{°}_f\left(B\right)\right]$

Here C and D are the products and A and B are the reactants, and c, d, a, and b are their respective stoichiometric coefficients.

The standard enthalpy of the formation of any element in its standard state is zero, which is also known as the most stable state.