This simulation emulates the gas phase equilibria between hydrogen, bromine and hydrogen bromide molecules.

http://weelookang.blogspot.sg/2014/12/hydrogen-bromine-hydrogen-bromide.html

H2 + Br2 ⇌ 2HBr (∆H = -103 kJ mol-1)

Constants:

kB = R / NA = 1.38060445E23

R = 8.314

NA = 6.022E-23

Parameters:

Hydrogen are white particles. (mass = 2*1.00794 u)

Bromine are red particles. (mass = 2* 79.904 u)

Hydrogen bromide are green particles. (mass = 79.904 + 1.00794 u)

N = 100 molecules

H-H bond: 436 kJ mol-1

Br-Br bond: 193 kJ mol-1

H-Br bond: 366 kJ mol-1

∆H = -103 kJ mol-1

kf = Aexp(-629/8.314/T)

kb = Aexp(-732/8.314/T)

Keq = kf/kb = exp(103/8.314/T)

Fixed relations

v = Math.sqrt(3*8.314/6.022*10E23*T/mass)