Acetic acid (CH3COOH) dissociates in water and exists in equilibrium with its ions according to the following chemical equation: СНЗСООН аq %3D СНЗСОО-аq+H+аq The value of the equilibrium constant at 25°C is 1.8*10-5 What does this value tell you about the relative amount of reactant and products at equilibrium?

. What does it mean to say that a state of chemical or physical equilibrium is dynamic?

Based on the diagrams, chemical reaction, and reaction conditions depicted in Problem 9-81, for which of the diagrams is the numerical value of the equilibrium constant the smallest?

Consider the following reactions at some temperature: 2NOCl(g)2NO(g)+Cl2(g)K=1.6105 2NO(g)N2(g)+O2(g)K=11031 For each reaction, assume some quantities of the reactants were placed in separate containers and allowed to come to equilibrium. Describe the relative amounts of reactants and products that would be present at equilibrium. At equilibrium, which is faster, the forward or reverse reaction in each case?

For the system PCl5(g)PCl3(g)+Cl2(g)K is 26 at 300C. In a 1.0-L flask at 300C, a gaseous mixture consists of all three gases with the following partial pressures: PPCl5=0.026atm,PPCl3=0.65atmPPCl2=0.33atm (a) Is the system at equilibrium? Explain. (b) If the system is not at equilibrium, in which direction will the system move to reach equilibrium?

7-64 As we shall see in Chapter 20, there are two forms of glucose, designated alpha and betawhich are in equilibrium in aqueous solution. The equilibrium constant for the reaction is 1.5 at 30°C. (a) If you begin with a fresh 1.0 M solution of D-glucose in water, what will be its concentration when equilibrium is reached? (b) Calculate the percentage of glucose and of glucose present at equilibrium in aqueous solution at 30°C.

Because carbonic acid undergoes a second ionization, the student in Exercise 12.39 is concerned that the hydrogen ion concentration she calculated is not correct. She looks up the equilibrium constant for the reaction HCO,-(aq) «=* H+(aq) + COf'(aq) Upon finding that the equilibrium constant for this reaction is 4.8 X 10“H, she decides that her answer in Exercise 12.39 is correct. Explain her reasoning. A student is simulating the carbonic acid—hydrogen carbonate equilibrium in a lake: H,CO,(aq) 5=6 H+(aq) + HCO,'(aq) K = 4.4 X 10'7She starts with 0.1000 A1 carbonic acid. W hat are the concentrations of all species at equilibrium?

The equilibrium between nitrogen monoxide, oxygen, and nitrogen dioxide may be expressed in the equation 2NO(g)+O2(g)2NO(g). Write the equilibrium constant expression for this equation. Then express the same equilibrium in at least two other ways, and write the equilibrium constant expression for each. Are the constants numerically equal? Cite some evidence to support your answer. Nitrogen monoxide and oxygen, both colorless gases, react to form reddish-brown nitrogen dioxide.

Because calcium carbonate is a sink for CO32- in a lake, the student in Exercise 12.39 decides to go a step further and examine the equilibrium between carbonate ion and CaCOj. The reaction is Ca2+(aq) + COj2_(aq) ** CaCO,(s) The equilibrium constant for this reaction is 2.1 X 10*. If the initial calcium ion concentration is 0.02 AI and the carbonate concentration is 0.03 AI, what are the equilibrium concentrations of the ions? A student is simulating the carbonic acid—hydrogen carbonate equilibrium in a lake: H2COj(aq) H+(aq) + HCO}‘(aq) K = 4.4 X 10"7 She starts with 0.1000 AI carbonic acid. What are the concentrations of all species at equilibrium?

Iodine chloride decomposes at high temperatures to iodine and chlorine gases. 2ICl(g)I2(g)+Cl2(g)Equilibrium is established at a certain temperature when the partial pressures of ICl, I2, and Cl2 are (in atm) 0.43, 0.16, and 0.27, respectively. (a) Calculate K. (b) If enough iodine condenses to decrease its partial pressure to 0.10 atm, in which direction will the reaction proceed? What is the partial pressure of iodine when equilibrium is reestablished?