1. The problem statement, all variables and given/known data One mole of oxygen at 27°C and at one atmospheric pressure is enclosed in a vessel. Assuming the molecules to be moving with Vrms, find the number of collisions per second which the molecules make with 1 m2 area of the vessel wall. 2. Relevant equations vrms = √(3RT/M) PV = nRT 3. The attempt at a solution I want to find the total number of collisions that the molecules make with a cube of side 1m and divide that by 6 to get the no. of collisions with one face. I know how to calculate pressure (using momentum etc), which gives the equation P = ⅓ ( mN/V ) (vrms)2 where m is the mass of one molecule, N total no. of molecules, V volume. I don't know how to combine all this information.