The gas-phase solid catalyzed reaction, 3H2 + N2 + 2NH3
is carried out over an iron catalyst and proceeds by the following mechanism,
H2 + 2S + 2H. S
N2 + 25 + 2N. S
N. S+H. S + HN. S+S
NH. S+HS H2N. S+S
H2N S + H S + NH4+SS
NH3:S + NH3 + S
Derive a rate law assuming that the dissociative adsorption of N2 is the rate limiting step. You may also assume that the dissociative adsorption of H2 is very weak, since this exothermic reaction is carried out at elevated temperatures.

in chemistry, adhesion and cohesion are attractive forces that exist between molecules. they hold the molecules together from each other. they are different in that adhesive force exists between molecules of different substance while cohesive force happens between molecules of same substance.

adhesion between water and glass causes water molecules at the edge of water and glass interface to climb up the wall in a narrow glass tube. this is called capillary action. cohesion is what gives glass its shape and causes water to form a droplet.