CHM 2045 Lecture Notes - Dimensionless Quantity, Molecularity, Viscosity
Document Summary
Rate determining step: if a complex reaction is separated into elementary steps: b. No2(g) + no2(g) no3(g) + no(g) slow step: 2. No3(g) + co(g) no2(g) + co2(g) fast step: 3. 2no(g) + br2(g) nobr2 fast step: 2. Nobr2(g) + no(g) 2nobr(g) slow step: 3. [nobr2] depends upon the first step; if we assume it reaches equilibrium very quickly: reversible reaction rates: second step rate-determining example, reversible reaction rates: equilibrium approximation. [nobr2] can be written in terms of the equilibrium constant kc for step 1, [nobr2] = Or we can use equilibrium approximation: a. equilibrium approximation assumes all steps prior to the rate-limiting step are in, b. Approximation: reversible reaction rates: steady state approximation, a. Liquid molecules make ~100 times more collisions per second that gas molecules because of the closer proximity; however, most are between solvent molecules and thus don"t result in a reaction: b.