1. A cubical box of 0.1 m on a side contains 3 x1022 molecules of 02 at 300 K. (a) On the average, how many collisions does each molecule make with the walls of I he box in one second? (b) Whir pressure does I he oxygen exert on arch walls of I he box? 2. A closed vessel contains liquid water in equilibrium with its vapor al 1000c and I arm. One gram of water vapor al I his rerun premature and pressure occupies a volume of 1670 cm2 The heal of vaporization at the temperature is 2250 J g-1 (a) How many molecules are there per cm2 of vapor? (b) How many vapor molecules mike each cm2 of liquid surface per second? (c) If each molecule which strikes the surface condenses, how many evaporate from each cm2 per second? (d) Compare the mean kinetic energy of a vapor molecule with the energy required 10 transfer one molecule from the liquid 10 the vapor phase.