Passage IV
Atmospheres (atm), torr, and kilopascals (kPa) are common units of pressure. Figure 1 can be used to convert between torr and kPa. A pressure of 1 atm is indicated in Figure 1.
Figure 2 shows how boiling point (BP) varies with atmospheric pressure for 3 compounds: acetaldehyde, acetone, and pentane. The unit of pressure is torr.
Figure 3 shows how BP varies with atmospheric pressure for 3 other compounds: ethanol, methanol, and methyl acetate. The unit of pressure is kPa.
23. According to Figure 2, the BP of pentane at 700 torr is closest to the BP of acetaldehyde at which of the following atmospheric pressures?
Your Answer is
Correct Answer is D
Explanation
Looking at figure 2, when the abscissa is 700 torr, the ordinate of pentane is about 34°C, and if the BP of acetaldehyde is to reach 34°C, the pressure must be above 1000 torr, and only option D is the closest< /p>