版权所有：华东理工大学物理化学教研室 15 Method: The equilibrium constant is obtained from the standard Gibbs energy of reaction, so we need to relate the degree of dissociation, α, to K and then to find its numerical value. Proceed by expressing the equilibrium compositions in terms of α, and solve for α in terms of K. Because the standard Gibbs energy of reaction is large and positive, we can anticipate that K will be small, and hence that α << 1, which opens the way to making approximations to obtain its numerical value. Example版权所有：华东理工大学物理化学教研室 15 Method: The equilibrium constant is obtained from the standard Gibbs energy of reaction, so we need to relate the degree of dissociation, α, to K and then to find its numerical value. Proceed by expressing the equilibrium compositions in terms of α, and solve for α in terms of K. Because the standard Gibbs energy of reaction is large and positive, we can anticipate that K will be small, and hence that α << 1, which opens the way to making approximations to obtain its numerical value. Example