Urgent Help Needed!! (gases) I need some urgent help with figuring out how to find the distance which 2 gases will meet in this question.. Given: Samples of HBr gas and NH_3 gas are placed at opposite ends of a 1.80 m tube. Question: If the two gases are allowed to diffuse through the tube toward one another, at what distance from each end of the tube will the gases meet and form solid NH_4Br? Thank you to anyone who can help me with this, or at least set me in the right path. The distance must be in Cm as well..