CHEM 120 Lecture Notes - Lecture 6: Third Order, Reaction Rate Constant, Titration

• School: McGill University
• Department: Chemistry
• Course: CHEM 120
• Professor: Laura Pavelka

Document Summary

Chem 120 lecture 6 chemical kinetics. Chemical kinetics is concerned with the speed (or rate) at which the chemical reactions take place and the mechanisms by which they occur. A reaction mechanism is a step-by-step sequence of chemical events by which reactant molecules are turned into product molecules. The rate at which a reaction proceeds depends on the mechanism, so by measuring rates, we can hope to better understand mechanisms. Example: redox reaction: 2fe3+ (aq) + sn2+ (aq) 2fe2+ (aq) + sn4+ (aq) (delta[sn4+])/deltat = (delta[fe2+])/deltat = - (delta[fe3+])/deltat. Rate of disappearance is a negative quantity. Rate of formation is a positive quantity: doesn"t matter which you use for the rate, either appearance or disappearance of. Monortiable reaction: use gas burette to find rate of reaction that produces gas, or use titration, or use absorbance. Absorbance = a = ecl, e = molar extinction coefficient. Determining & using an initial rate of reaction.