kinetics_lecture2_F10

kinetics_lecture2_F10 - Kinetics of a Homogeneous Reaction...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Kinetics of a Homogeneous Reaction Objectives : Determine how reactant concentration affects the rate of reaction between 2,4-dinitrochlorobenzene (DNCB) and piperidine Determine how temp affects reaction rate + 2 N H Cl NO 2 NO 2 NO 2 NO 2 N + N H 2 Cl DNCB Pip DNPP Pip:HCl 2,4-d in itrop henyl p iperidine
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Rate Law A + B → C rate is proportional to reactant concentration v = d[C]/dt = -d[A]/dt = -d[B]/dt = k [A] m [B] n where k = rate constant m, n = order of individual reactant m + n = overall order of reaction k independent of concentration, but function of temperature and pressure rate law is experimentally determined m and n not always tied to stoichiometry
Background image of page 2
Order of Reaction Zero order (catalyzed decay of ammonia) Example: 2NH 3 N 2 + 3H 2 V = k First order (decay of C-14 ) Example: V = -d[ ]/dt = k [ ] Second order Example: DNCB + 2 Pip DNPP + Pip.HCl V = k[DNCB][Pip] β + N C 14 7 14 6 C 14 6 C 14 6
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Order and Stoichiometry Occasionally reaction order equals the stoichiometric coefficients H 2 + I 2 2 HI V = k [H 2 ][I 2 ] May be an indication of an elementary reaction More often order is not equal to stoichiometry H 2 + Br 2 2 HBr V = k [H 2 ] [Br 2 ] 3/2 [Br 2 ] + k’ [HBr]
Background image of page 4
Learning Check Which of the following must be true about the order of a reaction with respect to a component? a) equal to the stoichiometric coefficient b) an integer c) non-zero d) positive e) none of the above
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Reaction order under simplifying initial conditions A + 2B → C V = k[A][B] (mixed second order) From mixed second order to second order If [B] o = 2[A] o , [B] = 2[A] for all time, and V = 2k[A] 2 From mixed second order to pseudo-first order If [B] o >> [A] o , [B] changes very little during reaction, V = k[A][B] o = k’[A] where k’ = k[B] o
Background image of page 6
Differential and Integrated Rate Laws First Order Example O 3 O 2 + O Differential Rate Law: V = -d[O 3 ]/dt = k[O 3 ] Integrated rate law = t O O kdt O O d t o 0 ] [ ] [ 3 3 3 3 ] [ ] [ kdt O O d = ] [ ] [ 3 3 kt O O n o t = ] [ ] [ 3 3
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/07/2011 for the course CHEM 356 taught by Professor Rowell during the Summer '10 term at Drexel.

Page1 / 23

kinetics_lecture2_F10 - Kinetics of a Homogeneous Reaction...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online