Lecture 4 Chemistry Lecture Notes - Kinetics and Colligative Properties

Flashcards for Chemistry Lecture Review

Van't Hoff factor (i)

The ratio of moles of solute particles to moles of formula units/molecules dissolved. It indicates the extent of dissociation or association of a solute in a solution.

Theoretical van't Hoff factor

Equals the number of ions in one unit of the compound if the solute dissociates 100%

Percent Dissociation

((i - 1) / (imax - 1)) * 100%, where i is the observed van't Hoff factor and imax is the expected van't Hoff factor at 100% dissociation.

Ion Pairing

The association of oppositely charged ions with each other in solution, leading to a lower observed van't Hoff factor than expected.

Colligative Properties and Electrolytic Solutes

When a solute dissociates, the Van't Hoff factor needs to be included in the colligative properties formulas.

Chemical Kinetics

The study of the rates/speeds of reactions, including factors that impact the reaction rate and how they can be changed.

Collision Model

A reaction takes place between particles when they collide. Factors that increase the frequency and/or energy of collisions between particles will increase the rate of the reaction.

Reaction Rate

Measured as the change in amount of a reactant or product over time (∆amount / ∆time).

Generalized Rate of Reaction

Uses stoichiometric coefficients to normalize the individual changes in concentration, providing a consistent rate for the entire reaction.

Average Rate

The rate of a reaction over a time interval, which can change as the reaction proceeds.

Instantaneous Rate

The rate of the reaction at a specific instant of time, equal to the slope of the tangent at that time point on a curve of concentration vs. time.