Problem 60
Consider the reaction: \(2 \mathrm{SO}_{2}(g)+\mathrm{O}_{2}(g) \rightleftarrows 2 \mathrm{SO}_{3}(g) \quad \Delta H^{\circ}=-198.2 \mathrm{~kJ} / \mathrm{mol}\) Comment on the changes in the concentrations of \(\mathrm{SO}_{2}\), \(\mathrm{O}_{2},\) and \(\mathrm{SO}_{3}\) at equilibrium if we were to (a) increase the temperature, (b) increase the pressure, (c) increase \(\mathrm{SO}_{2}\), (d) add a catalyst, (e) add helium at constant volume.
Problem 61
In the uncatalyzed reaction: $$ \mathrm{N}_{2} \mathrm{O}_{4}(g) \rightleftarrows 2 \mathrm{NO}_{2}(g) $$ the pressure of the gases at equilibrium are \(P_{\mathrm{N}_{2} \mathrm{O}_{4}}=0.377\) atm and \(P_{\mathrm{NO}_{2}}=1.56 \mathrm{~atm}\) at \(100^{\circ} \mathrm{C}\). What would happen to these pressures if a catalyst were added to the mixture?
Problem 62
In the uncatalyzed reaction: $$ \mathrm{N}_{2} \mathrm{O}_{4}(g) \rightleftarrows 2 \mathrm{NO}_{2}(g) $$ the pressure of the gases at equilibrium are \(P_{\mathrm{N}_{2} \mathrm{O}_{4}}=0.377\) atm and \(P_{\mathrm{NO}_{2}}=1.56\) atm at \(100^{\circ} \mathrm{C}\). What would happen to these pressures if a catalyst were added to the mixture?
Problem 63
Consider the following equilibrium reaction in a closed container: $$ \mathrm{CaCO}_{3}(s) \rightleftarrows \mathrm{CaO}(s)+\mathrm{CO}_{2}(g) $$ What will happen if (a) the volume is increased, (b) some \(\mathrm{CaO}\) is added to the mixture, \((\mathrm{c})\) some \(\mathrm{CaCO}_{3}\) is removed, \(\left(\right.\) d) some \(\mathrm{CO}_{2}\) is added to the mixture, (e) a few drops of an \(\mathrm{NaOH}\) solution are added to the mixture, (f) a few drops of an HCl solution are added to the mixture (ignore the reaction between \(\mathrm{CO}_{2}\) and water), (g) temperature is increased?
Problem 67
Pure nitrosyl chloride (NOCl) gas was heated to \(240^{\circ} \mathrm{C}\) in a \(1.00-\mathrm{L}\) container. At equilibrium, the total pressure was 1.00 atm and the \(\mathrm{NOCl}\) pressure was 0.64 atm: $$ 2 \mathrm{NOCl}(g) \rightleftarrows 2 \mathrm{NO}(g)+\mathrm{Cl}_{2}(g) $$ (a) Calculate the partial pressures of \(\mathrm{NO}\) and \(\mathrm{Cl}_{2}\) in the system. (b) Calculate the equilibrium constant \(K_{P}\).
Problem 68
Consider the equilibrium system \(3 \mathrm{~A} \rightleftarrows \mathrm{B}\). Sketch the changes in the concentrations of \(\mathrm{A}\) and \(\mathrm{B}\) over time for the following situations: (a) initially only \(\mathrm{A}\) is present, (b) initially only B is present, (c) initially both A and \(B\) are present (with A in higher concentration). In each case, assume that the concentration of \(\mathrm{B}\) is higher than that of \(\mathrm{A}\) at equilibrium.
Problem 69
Baking soda (sodium bicarbonate) undergoes thermal decomposition as follows: $$ 2 \mathrm{NaHCO}_{3}(s) \rightleftarrows \mathrm{Na}_{2} \mathrm{CO}_{3}(s)+\mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(g) $$ Would we obtain more \(\mathrm{CO}_{2}\) and \(\mathrm{H}_{2} \mathrm{O}\) by adding extra baking soda to the reaction mixture in (a) a closed vessel or (b) an open vessel?
Problem 70
Consider the following reaction at equilibrium: $$\mathrm{A}(g) \rightleftarrows 2 \mathrm{~B}(g)$$ From the data shown here, calculate the equilibrium constant (both \(K_{P}\) and \(K_{\mathrm{c}}\) ) at each temperature. Is the reaction endothermic or exothermic? $$ \begin{array}{clc} \text { Temperature }\left({ }^{\circ} \mathbf{C}\right) & {[\mathbf{A}](\boldsymbol{M})} & {[\mathbf{B}](\boldsymbol{M})} \\ \hline 200 & 0.0125 & 0.843 \\ 300 & 0.171 & 0.764 \\ 400 & 0.250 & 0.724 \end{array} $$
Problem 71
The equilibrium constant \(K_{P}\) for the reaction: $$ 2 \mathrm{H}_{2} \mathrm{O}(g) \rightleftarrows 2 \mathrm{H}_{2}(g)+\mathrm{O}_{2}(g) $$ the same temperature? (b) The very small value of \(K_{P}\) (and \(K_{\mathrm{c}}\) ) indicates that the reaction overwhelmingly favors the formation of water molecules. Explain why, despite this fact, a mixture of hydrogen and oxygen gases can be kept at room temperature without any change.
Problem 75
Consider the following reaction at a certain temperature: $$ \mathrm{A}_{2}+\mathrm{B}_{2} \rightleftarrows 2 \mathrm{AB} $$ The mixing of 1 mole of \(\mathrm{A}_{2}\) with 3 moles of \(\mathrm{B}_{2}\) gives rise to \(x\) mole of \(\mathrm{AB}\) at equilibrium. The addition of 2 more moles of \(\mathrm{A}_{2}\) produces another \(x\) mole of \(\mathrm{AB}\). What is the equilibrium constant for the reaction?
