Carbon disulfide (CS2) is a toxic, highly flammable substance. The following thermodynamic data are available for CS2(l) and CS2(g) at 298 K:
|
ΔHfo(kJ/mol) |
ΔGfo(kJ/mol) |
| CS2(I) |
89.7 |
65.3 |
| CS2(g) |
117.4 |
67.2 |
(a) Draw the Lewis structure of the molecule. What do you predict for the bond order of the C - S bonds?
(b) Use the VSEPR method to predict the structure of the CS2 molecule.
(c) Liquid CS2 burns in O2 with a blue flame, forming CO2(g) and SO2(g). Write a balanced equation for this reaction.
(d) Using the data in the preceding table and in Appendix C, calculate ?H° and ?G° for the reaction in part (c). Is the reaction exothermic? Is it spontaneous at 298 K?
(e) Use the data in the table to calculate ?S° at 298 K for the vaporization of CS2(l). Is the sign of ?S°as you would expect for a vaporization?
(f) Using data in the table and your answer to part (e), estimate the boiling point of CS2(l). Do you predict that the substance will be a liquid or a gas at 298 K and 1 atm?