Chapter_14_Chemical_Kinetics[1] - Chapter 14 Chemical...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 14 Chemical Kinetics Chemical kinetics – the area of chemistry that is concerned with the speeds, or rates, of reactions 14.1 Factors that Affect Reaction rates Reactions involve the breaking and the forming of bonds, and their species depend on the nature of the reactants themselves Characteristics that Affect Reactions Rates are : 1. The Physical State of the Reactants - Reactants must come together in order to react - The more readily molecules collide, the more rapidly they react - Most reactions are homogeneous, however, when one is a gas and the other is a solid (heterogeneous), the reaction is limited to the area of contact. Increasing the area of the solids, increases the reaction rate. 2. The Concentrations of the Reactants - Increase the concentration of one or more of the reactants, the reaction rate is increased. - The more concentrated, the greater the frequency of the collisions between the molecules increases, thus increasing the rate 3. The Temperature at which the Reaction Occurs - Rate increases as the temperature increases 4. The Presence of a Catalyst - Catalyst – agent that increases reaction rates without being used up - The greater the frequency of collisions, the greater the rate of reaction 14.2 Reactions Rates - Reaction rate- the speed of a chemical reaction. Change in concentration of the reactants or products per unit time expressed in Molarity/sec (M/sec).
Background image of page 1

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

View Full DocumentRight Arrow Icon
For the reaction: A B - Rate of the reaction can be expressed either as the rate of disappearance of reactant A or the rate of appearance of product B. - Average Rate of Appearance of B = change in conc. of B/change in time = [B]at time 2 – [B] at time 1/ t 2 – t 1 = [B]/ t - Average Rate of Disappearance of A = - [A]/ t The negative is indicative of the rate of disappearance Change in Rate with Time - Instantaneous rate – the rate at a particular moment in the reaction. With a graph, it can be determined from the slope (or tangent) of the
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 7

Chapter_14_Chemical_Kinetics[1] - Chapter 14 Chemical...

This preview shows document pages 1 - 3. Sign up to view the full document.

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