Lecture Presentation Chapter 10 Reaction Rates and Chemical Equilibrium Karen C Timberlake General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Chapter Reaction Rates and Chemical Equilibrium A neonatal nurse works with newborns that are premature or have birth defects, cardiac malformations, and surgical problems Most neonatal nurses care for infants from the time of birth until the time they are discharged from the hospital General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Chapter 10 Readiness Key Math Skills • • Solving Equations (1.4D) Writing Numbers in Scientific Notation (1.4F) Core Chemistry Skills • • • Using Significant Figures in Calculations (2.3) Balancing a Chemical Equation (7.1) Calculating Concentration (9.4) General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc 10.1 Rates of Reactions Reaction rates vary greatly for everyday processes A banana ripens in a few days, silver tarnishes in a few months, while the aging process of humans takes many years Learning Goal Describe how temperature, concentration, and catalysts affect the rate of a reaction General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Rates of Reaction Reacting molecules must collide, have a minimum amount of energy, and have the proper orientation to form products General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Activation Energy • Even when a collision has the proper orientation, there still must be sufficient energy to break the bonds between the atoms of the reactants Three Conditions Required for a Reaction to Occur Collision The reactants must collide Orientation The reactants must align properly to Energy The collision must provide the energy General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake break and form bonds of activation © 2016 Pearson Education, Inc Activation Energy • The activation energy is the minimum amount of energy required to break the bonds between atoms of the reactants General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Rate of Reaction The rate (or speed) of a reaction is determined by measuring the amount of • • reactant used up in a certain period of time product formed in a certain period of time General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Factors That Affect the Rate of a Reaction Reactions with low activation energies go faster than reactions with high activation energies For any reaction, the rate is affected by • • • changes in temperature changes in reaction concentration adding a catalyst General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Rate of Reaction: Temperature At higher temperatures the increase in kinetic energy of the reactant molecules • • • makes them move faster makes them collide more often makes them collide with more energy For every 10 °C increase in temperature, most reaction rates approximately double General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Effect of Volume Change on Equilibrium: Decreasing Volume A change in the volume of a gas mixture at equilibrium will change the concentration of the gases in the mixture 2CO(g) + O2(g) 2CO2(g) Decrease Volume Decreasing the volume increases the concentration of the gases, and the system shifts in the direction of the smaller number of moles to compensate General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Effect of Volume Change on Equilibrium: Increasing Volume A change in the volume of a gas mixture at equilibrium will change the concentration of the gases in the mixture 2CO(g) + O2(g) 2CO2(g) Increase volume Increasing the volume decreases the concentration of the gases, and the system shifts in the direction of the larger number of moles to compensate General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Effect of Volume Change on Equilibrium (a) A decrease in the volume of the container causes the system to shift in the direction of fewer moles of gas (b) An increase in the volume of the container causes the system to shift in the direction of more moles of gas General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Chemistry Link to Health: Hb Oxygen transport involves an equilibrium between hemoglobin (Hb), oxygen, and oxyhemoglobin (HbO2) Hb(aq) + O2(g) • HbO2(aq) When there is a high concentration of O2 in the alveoli of the lungs, the reaction shifts in the direction of oxyhemoglobin • When the concentration of O2 is low in the tissues, the reverse reaction releases O2 from oxyhemoglobin General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Chemistry Link to Health: Hb Given the reaction of hemoglobin, Hb(aq) + O2(g) • HbO2(aq) At normal atmospheric pressure, oxygen diffuses into the blood because the partial pressure of oxygen in the alveoli is higher than that in the blood • At altitudes above 8000 ft, a decrease in atmospheric pressure results in a lower pressure of O General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Chemistry Link to Health: Hb At an altitude of 18,000 ft, a person will obtain 29% less oxygen and may experience hypoxia Hypoxia may occur at high altitudes where the oxygen concentration is lower General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Chemistry Link to Health: Hb According to Le Châtelier’s principle, a decrease in oxygen • • shifts the equilibrium in the direction of the reactants depletes the concentration of HbO2, causing hypoxia Remove O2 Hb(aq) + O2(g) HbO2(aq) General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Effect of Temperature Change on Equilibrium: Decreasing Temperature Decreasing the temperature of an endothermic reaction • • causes the system to respond by shifting the reaction toward more heat shifts the reaction toward the reactants, increasing heat in system N2(g) + O2(g) + heat 2NO(g) Decrease Temperature General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Effect of Temperature Change on Equilibrium: Increasing Temperature Increasing the temperature of an endothermic reaction • • causes the system to respond by shifting the reaction to remove heat shifts the reaction toward the products, using up the heat H2(g) + O2(g) + heat General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake Increase Temperature 2NO(g) © 2016 Pearson Education, Inc Effect of Temperature Change on Equilibrium: Decreasing Temperature Decreasing the temperature of an exothermic reaction • • causes the system to respond by shifting the reaction toward more heat shifts the reaction toward the products, increasing heat in system 2SO2(g) + O2(g) 2SO3(g) + heat Decrease Temperature General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Effect of Temperature Change on Equilibrium: Increasing Temperature Increasing the temperature of an exothermic reaction • • causes the system to respond by shifting the reaction toward removing heat shifts the reaction toward the reactants, decreasing heat in system 2SO2(g) + O2(g) 2SO3(g) + heat Increase Temperature General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Effects of Changing Conditions on Equilibrium General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Study Check Indicate the shift in equilibrium of each change 2NO2(g) + heat 1) toward products A B C D E 2) toward reactants adding more NO decreasing the temperature removing some O2 increasing the volume removing some NO General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake 2NO(g) + O2(g) © 2016 Pearson Education, Inc Study Check Indicate the shift in equilibrium of each change 2NO2(g) + heat 1) toward products A B C D E 2) toward reactants adding more NO 2) toward reactants decreasing the temperature 2) toward reactants removing some O2 1) toward products increasing the volume 1) toward products removing some NO 1) toward products General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake 2NO(g) + O2(g) © 2016 Pearson Education, Inc Concept Map General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc ... catalysts and are converted to CO 2, N2, O2, and H2O General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc General, Organic, and Biological. .. consumed General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Factors That Affect Reaction Rates General, Organic, and Biological Chemistry: ... such as octane (C8H18), and nitrogen oxide (NO) General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Chemistry Link to the Environment: