Chapter 23, Problem 23.44P

Interpretation Introduction

Interpretation:

Value of $\Delta H_{rxn}^o$ has to be determined for the reaction $B{r}_2\left(g\right)\underset{}{\overset{}{\rightleftharpoons }}\text{ 2 Br}\left(g\right)$ using the given data. Also, it has to be compared with the value obtained from Appendix D.

Given table is shown below,

  $\begin{array}{cc}T/K& K_p/{10}^{-3}\text{ bar}\\ \begin{array}{l}850\\ 900\\ 950\\ 1000\end{array}& \begin{array}{l}0.608\\ 1.47\\ 3.30\\ 6.97\end{array}\end{array}$

Concept Introduction:

Enthalpy is the total amount of heat in a particular system.

Value of $\Delta H_{rxn}^o$ can be calculated by the equation:

  $\Delta H_{rxn}^o\text{= }H°\left[\text{products}\right]-H°\left[\text{reactants}\right]$

van’t Hoff equation is given below,

  $\text{ln}\frac{{\text{K}}_{\text{2}}}{{\text{K}}_{\text{1}}}\text{=}\frac{{\text{ΔH}}_{rxn}^o}{\text{R}}\left[\frac{T_2-T_1}{T_1{T}_2}\right]$

Here, K₁ and K₂ are the vapor pressures at the Kelvin temperatures T₁ and T₂.