Liquid methyl ethyl ketone (mek) is introduced into a vessel containing air. the system temperature is increased to 55 ⁰c, and the vessel contents reach equilibrium with some mek remaining in the liquid state. the equilibrium pressure is 1200 mmhg. mixtures of mek vapor and air that contain between 1.8 mole% mek and 11.5moles% mek can ignite and burn explosively if exposed to a flame or spark. determine whether or not the given vessel constitutes an explosion hazard.