Which of the following exhibits the lowest vapor pressure at room temperature and why? A) CCl4 B) KF C) O2 D) H2O E) Hg Which of the following exhibits the lowest vapor pressure at room temperature and why? A) CCl4 B) KF C) O2 D) H2O E) Hg A) CCl4 B) KF C) O2 D) H2O E) Hg Solution Solution :- KF will have lowest vapor pressure among the given list because KF is the ionic compound so it has the strongest bond. KF is the solid therefore its vapor pressure is lowest ( almost none ) .