The Vapor Pressure of SnCl₄ Reaches 400 Mm Hg at 92

Multiple Choice

The vapor pressure of SnCl₄ reaches 400 mm Hg at 92 °C, the vapor pressure of SnI₄ reaches 400 mm Hg at 315 °C, the vapor pressure of PBr₃ reaches 400 mm Hg at 150 °C, and the vapor pressure of PCl₃ reaches 400 mm Hg at 57 °C. At 175 °C which substance would have the lowest vapor pressure?

A) PBr₃
B) SnI₄
C) SnCl₄
D) PCl₃