Problem 110
Given the following data: $$ \begin{array}{ll}{\mathrm{NO}_{2}(g) \longrightarrow \mathrm{NO}(g)+\mathrm{O}(g)} & {\Delta H=233 \mathrm{kJ}} \\ {2 \mathrm{O}_{3}(g) \longrightarrow 3 \mathrm{O}_{2}(g)} & {\Delta H=-427 \mathrm{kJ}}\end{array} $$ $$ \mathrm{NO}(g)+\mathrm{O}_{3}(g) \longrightarrow \mathrm{NO}_{2}(g)+\mathrm{O}_{2}(g) \quad \Delta H=-199 \mathrm{kJ} $$ Calculate the bond energy for the \(\mathrm{O}_{2}\) bond, that is, calculate \(\Delta H\) for: $$ \mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{O}(g) \qquad \Delta H=? $$
Problem 111
If a student performs an endothermic reaction in a calorimeter, how does the calculated value of \(\Delta H\) differ from the actual value if the heat exchanged with the calorimeter is not taken into account?
Problem 112
In a bomb calorimeter, the reaction vessel is surrounded by water that must be added for each experiment. Since the amount of water is not constant from experiment to experiment, the mass of water must be measured in each case. The heat capacity of the calorimeter is broken down into two parts: the water and the calorimeter components. If a calorimeter contains 1.00 \(\mathrm{kg}\) water and has a total heat capacity of \(10.84 \mathrm{kJ} / \mathrm{C},\) what is the heat capacity of the calorimeter components?
Problem 113
The bomb calorimeter in Exercise 112 is filled with 987 \(\mathrm{g}\) water. The initial temperature of the calorimeter contents is \(23.32^{\circ} \mathrm{C} .\) A \(1.056-\mathrm{g}\) sample of benzoic acid \(\left(\Delta E_{\mathrm{comb}}=\right.\) \(-26.42 \mathrm{kJ} / \mathrm{g}\) ) is combusted in the calorimeter. What is the final temperature of the calorimeter contents?
Problem 115
Consider the following equations: $$ \begin{array}{ll}{3 \mathrm{A}+6 \mathrm{B} \longrightarrow 3 \mathrm{D}} & {\Delta H=-403 \mathrm{kJ} / \mathrm{mol}} \\ {\mathrm{E}+2 \mathrm{F} \longrightarrow \mathrm{A}} & {\Delta H=-105.2 \mathrm{kJ} / \mathrm{mol}} \\\ {\mathrm{C} \longrightarrow \mathrm{E}+3 \mathrm{D}} & {\Delta H=64.8 \mathrm{kJ} / \mathrm{mol}}\end{array} $$ Suppose the first equation is reversed and multiplied by \(\frac{1}{6},\) the second and third equations are divided by \(2,\) and the three adjusted equations are added. What is the net reaction and what is the overall heat of this reaction?
Problem 116
Given the following data $$ \begin{array}{ll}{\mathrm{Fe}_{2} \mathrm{O}_{3}(s)+3 \mathrm{CO}(g) \longrightarrow 2 \mathrm{Fe}(s)+3 \mathrm{CO}_{2}(g)} & {\Delta H^{\circ}=-23 \mathrm{kJ}} \\ {3 \mathrm{Fe}_{2} \mathrm{O}_{3}(s)+\mathrm{CO}(g) \longrightarrow 2 \mathrm{Fe}_{3} \mathrm{O}_{4}(s)+\mathrm{CO}_{2}(g)} & {\Delta H^{\circ}=-39 \mathrm{kJ}} \\ {\mathrm{Fe}_{3} \mathrm{O}_{4}(s)+\mathrm{CO}(g) \longrightarrow 3 \mathrm{FeO}(s)+\mathrm{CO}_{2}(g)} & {\Delta H^{\circ}=18 \mathrm{kJ}}\end{array} $$ calculate \(\Delta H^{\circ}\) for the reaction $$ \mathrm{FeO}(s)+\mathrm{CO}(g) \longrightarrow \mathrm{Fe}(s)+\mathrm{CO}_{2}(g) $$
Problem 117
At 298 \(\mathrm{K}\) , the standard enthalpies of formation for \(\mathrm{C}_{2} \mathrm{H}_{2}(g)\) and \(\mathrm{C}_{6} \mathrm{H}_{6}(l)\) are 227 \(\mathrm{kJ} / \mathrm{mol}\) and \(49 \mathrm{kJ} / \mathrm{mol},\) respectively. a. Calculate \(\Delta H^{\circ}\) for $$ \mathrm{C}_{6} \mathrm{H}_{6}(l) \longrightarrow 3 \mathrm{C}_{2} \mathrm{H}_{2}(g) $$ b. Both acetylene \(\left(\mathrm{C}_{2} \mathrm{H}_{2}\right)\) and benzene \(\left(\mathrm{C}_{6} \mathrm{H}_{6}\right)\) can be used as fuels. Which compound would liberate more energy per gram when combusted in air?
Problem 118
Using the following data, calculate the standard heat of formation of ICl \((g)\) in \(\mathrm{kJ} / \mathrm{mol} :\) $$\begin{array}{ll}{\mathrm{Cl}_{2}(g) \longrightarrow 2 \mathrm{Cl}(g)} & {\Delta H^{\circ}=242.3 \mathrm{kJ}} \\ {\mathrm{I}_{2}(g) \longrightarrow 2 \mathrm{I}(g)} & {\Delta H^{\circ}=151.0 \mathrm{kJ}} \\ {\mathrm{ICl}(g) \longrightarrow \mathrm{I}(g)+\mathrm{Cl}(g)} & {\Delta H^{\circ}=211.3 \mathrm{kJ}} \\ {\mathrm{I}_{2}(s) \longrightarrow \mathrm{I}_{2}(g)} & {\Delta H^{\circ}=62.8 \mathrm{kJ}}\end{array}$$
Problem 119
A sample of nickel is heated to \(99.8^{\circ} \mathrm{C}\) and placed in a coffeecup calorimeter containing 150.0 \(\mathrm{g}\) water at \(23.5^{\circ} \mathrm{C}\) . After the metal cools, the final temperature of metal and water mixture is \(25.0^{\circ} \mathrm{C}\) . If the specific heat capacity of nickel is 0.444 \(\mathrm{J} /^{\prime} \mathrm{C} \cdot \mathrm{g}\) what mass of nickel was originally heated? Assume no heat loss to the surroundings.
Problem 120
Given: $$ \begin{array}{ll}{2 \mathrm{Cu}_{2} \mathrm{O}(s)+\mathrm{O}_{2}(g) \longrightarrow 4 \mathrm{CuO}(s)} & {\Delta H^{\circ}=-288 \mathrm{kJ}} \\\ {\mathrm{Cu}_{2} \mathrm{O}(s) \longrightarrow \mathrm{CuO}(s)+\mathrm{Cu}(s)} & {\Delta H^{\circ}=11 \mathrm{kJ}}\end{array} $$ Calculate the standard enthalpy of formation \(\left(\Delta H_{f}^{\circ}\right)\) for \(\mathrm{CuO}(s) .\)
