Passage II

Primary amines (PAs) are compounds containing an amino (NH2) group bound to a hydrocarbon chain (a group made up of C and H atoms). Table 1 lists, for each of 5 PAs, the chemical formula, molecular mass (mass of 1 molecule) in atomic mass units (amu), melting point (MP), and boiling point (BP).

Table 2 lists, for each of the 5 PAs, the flash point (the lowest temperature at which a flammable mixture is formed in the air above a liquid) and the temperature at which the vapor pressure (the pressure exerted by a vapor in equilibrium with its liquid state) equals 0.1 kPa, 1 kPa, 10 kPa, and 100 kPa.

Tables adapted from W. M. Haynes, ed., CRC Handbook of Chemistry and Physics on CD-ROM, Version 2011. ©2011 by CRC Press, LLC.

11. Consider the PA 1-octanamine, CH3(CH2)7NH2. Based on Tables 1 and 2, the temperature at which the vapor pressure of 1-octanamine equals 100 kPa would most likely be:

Answer and Explanation

Your Answer is

Correct Answer is D

Explanation

PA 1-octanamine in the question stem has one more CH2 than 1-heptanamine in Table 1 and Table 2. According to Table 2, the vapor pressure at 100kPa follows the CH2< in the chemical formula /sub>The number increases and increases, the vapor pressure of 1-octanamine should be greater than 1-heptanamine, choose D