Question

I don't know how to do these. Can you help?

The combustion of carbon monoxide is represented by the equation below:

CO(g) + ½O 2 (g) → CO 2 (g)

(a) (i) Determine the value of the standard enthalpy change, ΔH o rxn, for the combustion of CO(g) at
298 K using the following information. (3 pts)

C(s) + ½O 2 (g) → CO(g) ΔH o 298 = -110. 5 kJ mol -1
C(s) + O 2 (g) → CO 2 (g) ΔH o 298 = -393.5 kJ mol -1

(ii) Which is larger, the total bond dissociation energy of the reactants or the total bond
dissociation energy of the products? Explain. (2 pts)

(b) Determine the value of the standard entropy change, ΔS o rxn , for the combustion of CO(g) at 298
K using the information in the following table. (3 pts)
Substance S o 298(J mol -1 K -1 )
CO(g) 197.7
CO 2 (g) 213.7
O 2 (g) 205.1

(c) i) Determine the standard free energy change, ΔG o rxn , for the reaction at 298 K. Include units with
your answer. (3 pts)

ii) Is the reaction spontaneous under standard conditions at 298 K? Justify your answer. (2 pts)

(d) Calculate the value of the equilibrium constant, K eq , for the reaction at 298 K. (3 pts)

(e) Assume ∆H o and ∆S o for the reaction are independent of temperature.
(i) Explain why there is a temperature above 298 K at which the algebraic sign of the value of
∆G o changes. (2 pts)

(ii) Theoretically, the best yield of CO 2 should be achieved at low temperatures or high
pressures. Explain each. (hint: apply Le Chatelier’s principle) (2 pts)

EC a) Write a net ionic equation for: Lithium metal is strongly heated in nitrogen gas. (2 pts)

b) Predict the sign of ΔS° for the reaction at 25°C. Justify your prediction. (1 pt)

Answer 1