## Abstract

In this chapter, you will learn how to determine the rate of reactions, rate constants, and orders of reactions from balanced chemical equations and the rate law. There are clear descriptions of the zero- and first-order rate processes. You will use respective equations and *C*-*t* plots to determine the drug initial concentrations, rate constants, half-lives, shelf-lives, and drug concentrations at specified time intervals. You will understand the difference between the rate of reaction of a first-order process and the first-order rate constant, and you will learn how to use the leading coefficient and the input of first-order equation to compare the elimination profile of different drugs.

## Keywords

Rate Rate constant Reaction order Rate law Zero order First order Exponential functions Half-life Initial concentration## Supplementary material

Rates and orders of reactions—Part I. Description: (a) Rate of reactions, rate constants, and orders of reactions from balanced chemical equations and from the rate law. (b) Use of respective equations from C-t plots to determine rate constants and order of reactions (MP4 703019 kb)

Rates and orders of reactions—Part II: Zero-order reactions. Description: (a) Zero-order rate processes, and use respective equations and C-t plots to determine drug initial concentrations, rate constants, half-lives, and drug concentrations at specified time intervals. (b) Physical significance of a zero-order rate constant (MP4 711911 kb)

Rates and orders of reactions—Part III: First-order reactions. Description: (a) First-order rate processes, and use of respective equations and C-t plots to determine drug initial concentrations, rate constants, and half-lives (MP4 886901 kb)

Rates and orders of reactions—Part III: First-order reactions. Description: (a) First-order rate processes, and use of respective equations and C-t plots to determine drug initial concentrations, rate constants, half-lives, shelf-lives, and drug concentrations at specified time intervals. (b) The difference between the rate of reaction of a first-order process and the first-order rate constant. (c) Use of the leading coefficient and the input variable of first-order equation to compare the elimination profile of different drugs (MP4 844111 kb)

Rates and orders of reactions—Part V: Horizontal and vertical shifts of exponential functions. Description: (a) Perform vertical and horizontal shifts of exponential functions. (b) Apply vertical and horizontal shifts of exponential function to describe drug release and delayed drug release from dosage forms (MP4 288493 kb)