Constants Periodic Table Pentane is one of the most volatile of the hydrocarbons in gasoline. At 298.15 K, the following enthalpies of formation are given for pentane: Part C AT, [C5H12(1)] =-173.5 kJmol 1; Comment on the significance of the sign of Î.apGãfor pentane at 298 K. Match the words in the left column to the appropriate blanks in the sentences on the right. You may want to reference (Page) Section 13.1 while completing this problem. Resot Help spontaneous will occur 1.00 atm 1.00 bar The positive value of Î ap G indicates that nommal boiling having a vapor pressure of for pentane should be at 298 K. The vapor pressure of pentane at than 1.00 atm non-spontaneous (will not occur) Submit Request Answer