General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 1 Chapter 9 Chemical Equilibrium 9.1 Rates of Reactions

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 2 Collision Theory of Reactions A chemical reaction occurs when  collisions between molecules have sufficient energy to break the bonds in the reactants  molecules collide with the proper orientation  bonds between atoms of the reactants (N 2 and O 2 ) are broken and new bonds (NO) form

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 3 Collision Theory of Reactions (continued) A chemical reaction does not take place if the  collisions between molecules do not have sufficient energy to break the bonds in the reactants  molecules are not properly aligned

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 4 Activation Energy The activation energy  is the minimum energy needed for a reaction to take place upon proper collision of reactants

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 5 Reaction Rate and Temperature Reaction rate  is the speed at which reactant is used up  is the speed at which product forms  increases when temperature rises because reacting molecules move faster, thereby providing more colliding molecules with energy of activation

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 6 Reaction Rate and Concentration Increasing the concentration of reactants  increases the number of collisions  increases the reaction rate

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 7 Reaction Rate and Catalysts A catalyst  speeds up the rate of a reaction  lowers the energy of activation  is not used up during the reaction

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 8 Factors that Increase Reaction Rate

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 9 Learning Check State the effect of each on the rate of reaction as: I) increases D) decreases N) no change A. increasing the temperature B. removing some of the reactants C. adding a catalyst D. placing the reaction flask in ice E. increasing the concentration of a reactant

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 10 Solution State the effect of each on the rate of reaction as: I) increases D) decreases N) no change A. (I) increasing the temperature B. (D) removing some of the reactants C. (I) adding a catalyst D. (D) placing the reaction flask in ice E. (I) increasing the concentration of a reactant

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 11 Learning Check Indicate the effect of each factor listed on the rate of the following reaction as I) increases, D) decreases, or N) none: 2CO(g) + O 2 (g) 2CO 2 (g) A. raising the temperature B. removing O 2 C. adding a catalyst D. lowering the temperature

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 12 Solution Indicate the effect of each factor listed on the rate of the following reaction as I) increases, D) decreases, or N) none: 2CO(g) + O 2 (g) 2CO 2 (g) A. (I) raising the temperature B. (D)adding O 2 C. (I) adding a catalyst D. (D) lowering the temperature