Chapter 3, Problem 125AE

(a)

Interpretation Introduction

Interpretation: Using the given values of bond energy, the electron affinity and the ionization energy of hydrogen to be calculated for the given reactions.

Concept introduction: The change in energy for a given chemical equation is the sum of the bond energy, the ionization energy and the electron affinity values of the respective steps involved in the chemical reaction.

To determine: The change in energy for the given reaction, $HF\left(g\right)\to H^{+}\left(g\right)+F^{-}\left(g\right)$.

Answer to Problem 125AE

The change in energy is $\underset{\_}{1549.2kJmo{l}^{-1}}$

Explanation of Solution

Explanation:

The chemical reaction involved is,

$HF\left(g\right)\to H^{+}\left(g\right)+F^{-}\left(g\right)$

The various steps included in the total process are,

$HF\left(g\right)\to H\left(g\right)+F\left(g\right)$, bond energy $=565kJmo{l}^{-1}$

$H\left(g\right)\to H^{+}\left(g\right)+e^{-}$, ionization energy $=1312kJmo{l}^{-1}$

$F\left(g\right)+e^{-}\to F^{-}\left(g\right)$, electron affinity $=-327.8kJmo{l}^{-1}$

The total energy change $\begin{array}{l}=Bondenergy+Ionizationenergy+Electronaffinity\\ =\left(565+1312-327.8\right)kJmo{l}^{-1}\\ =\underset{\_}{1549.2kJmo{l}^{-1}}\end{array}$

Conclusion

The total energy change for a given chemical reaction is the sum of bond energy, the ionization energy and the electron affinity value of the respective steps involved in the reaction.

(b)

Interpretation Introduction

Interpretation: Using the given values of bond energy, the electron affinity and the ionization energy of hydrogen to be calculated for the given reactions.

Concept introduction: The change in energy for a given chemical equation is the sum of the bond energy, the ionization energy and the electron affinity values of the respective steps involved in the chemical reaction.

To determine: The change in energy for the given reaction, $HCl\left(g\right)\to H^{+}\left(g\right)+C{l}^{-}\left(g\right)$.

Answer to Problem 125AE

The change in energy is $\underset{\_}{1391kJmo{l}^{-1}}$

Explanation of Solution

The chemical reaction involved is,

$HCl\left(g\right)\to H^{+}\left(g\right)+C{l}^{-}\left(g\right)$

The various steps included in the total process are,

$HCl\left(g\right)\to H\left(g\right)+Cl\left(g\right)$, bond energy $=427kJmo{l}^{-1}$

$H\left(g\right)\to H^{+}\left(g\right)+e^{-}$, ionization energy $=1312kJmo{l}^{-1}$

$Cl\left(g\right)+e^{-}\to C{l}^{-}\left(g\right)$, electron affinity $=-348kJmo{l}^{-1}$

The total energy change $\begin{array}{l}=Bondenergy+Ionizationenergy+Electronaffinity\\ =\left(427+1312-348\right)kJmo{l}^{-1}\\ =\underset{\_}{1391kJmo{l}^{-1}}\end{array}$

Conclusion

The total energy change for a given chemical reaction is the sum of bond energy, the ionization energy and the electron affinity value of the respective steps involved in the reaction.

(c)

Interpretation Introduction

Interpretation: Using the given values of bond energy, the electron affinity and the ionization energy of hydrogen to be calculated for the given reactions.

Concept introduction: The change in energy for a given chemical equation is the sum of the bond energy, the ionization energy and the electron affinity values of the respective steps involved in the chemical reaction.

To determine: The change in energy for the given reaction, $HI\left(g\right)\to H^{+}\left(g\right)+I^{-}\left(g\right)$.

Answer to Problem 125AE

The change in energy is $\underset{\_}{1312kJmo{l}^{-1}}$.

Explanation of Solution

The chemical reaction involved is,

$HI\left(g\right)\to H^{+}\left(g\right)+I^{-}\left(g\right)$

The various steps included in the total process are,

$HI\left(g\right)\to H\left(g\right)+I\left(g\right)$, bond energy $=295kJmo{l}^{-1}$

$H\left(g\right)\to H^{+}\left(g\right)+e^{-}$, ionization energy $=1312kJmo{l}^{-1}$

$I\left(g\right)+e^{-}\to I^{-}\left(g\right)$, electron affinity $=-295kJmo{l}^{-1}$

The total energy change $\begin{array}{l}=Bondenergy+Ionizationenergy+Electronaffinity\\ =\left(295+1312-295\right)kJmo{l}^{-1}\\ =\underset{\_}{1312kJmo{l}^{-1}}\end{array}$

Conclusion

The total energy change for a given chemical reaction is the sum of bond energy, the ionization energy and the electron affinity value of the respective steps involved in the reaction.

(d)

Interpretation Introduction

Interpretation: Using the given values of bond energy, the electron affinity and the ionization energy of hydrogen to be calculated for the given reactions.

Concept introduction: The change in energy for a given chemical equation is the sum of the bond energy, the ionization energy and the electron affinity values of the respective steps involved in the chemical reaction.

To determine: The change in energy for the given reaction, $H_{2}O\left(g\right)\to H^{+}\left(g\right)+O{H}^{-}\left(g\right)$.

Answer to Problem 125AE

The change in energy is $\underset{\_}{1599kJmo{l}^{-1}}$.

Explanation of Solution

The chemical reaction involved is,

$H_{2}O\left(g\right)\to H^{+}\left(g\right)+O{H}^{-}\left(g\right)$

The various steps included in the total process are,

$H_{2}O\left(g\right)\to H\left(g\right)+OH\left(g\right)$, bond energy $=467kJmo{l}^{-1}$

$H\left(g\right)\to H^{+}\left(g\right)+e^{-}$, ionization energy $=1312kJmo{l}^{-1}$

$OH\left(g\right)+e^{-}\to O{H}^{-}\left(g\right)$, electron affinity $=-180kJmo{l}^{-1}$

The total energy change $\begin{array}{l}=Bondenergy+Ionizationenergy+Electronaffinity\\ =\left(467+1312-180\right)kJmo{l}^{-1}\\ =\underset{\_}{1599kJmo{l}^{-1}}\end{array}$

Conclusion

The total energy change for a given chemical reaction is the sum of bond energy, the ionization energy and the electron affinity value of the respective steps involved in the reaction.