a. Which of the following statements is true? The magnitude of K₂ is always independent of temperature. The magnitude of K, always depends on temperature. For some reactions K, depends on temperature, while for others it does not. b. Decide whether the following statement is true or false. When two chemical equations are added to give a net equation, the equilibrium constant for the net equation is the product of the equilibrium constants of the summed equations. false O true c. Which of the following statements is true? K of a reaction depends on undissolved solid reactant. K of a reaction does not depend on undissolved solid reactant and concentration of solvent. K of a reaction depends on concentration of solvent.

How is the strength of an acid related to the position of its ionization equilibrium? Write the equations for the dissociation (ionization) of HCI, HNO3, and HClO4in water. Since all these acids are strong acids, what does this indicate about the basicity of the Cl-, NO3, and ClO4ions? Are aqueous solutions of NaCl, NaNO3, or NaClO4basic?

Hard water has a high concentration of calcium and magnesium ions. Focusing on the calcium ion, a common home water -softening process is based on a reversible chemical change that can be expressed by Na2Ze(s)+Ca2+(aq)CaZe(s)+2Na+(aq). Na2Ze represents a solid resin that is like an ionic compound between sodium ions and zeolite ions, a complex arrangement of silicate and aluminate groups; CaZe is the corresponding calcium compound. When, during the day, is this system most likely to reach equilibrium? Why doesnt it reach equilibrium and stay there? Periodically it is necessary to recharge the water softner by running salt water, NaCl(aq), through it. Why is this necessary? What concept is discussed in this chapter does the recharging process illustrate? Zeolite ions are used in home water softners because they have a porous but rigid structure that is weakly attracted to cations, readily allowing an exchange among different ions.

Consider the system 4NH3(g)+3O2(g)2N2(g)+6H2O(l)H=1530.4kJ (a) How will the concentration of ammonia at equilibrium be affected by (1) removing O2(g)? (2) adding N2(g)? (3) adding water? (4) expanding the container? (5) increasing the temperature? (b) Which of the above factors will increase the value of K? Which will decrease it?

The density of trifluoroacetic acid vapor was determined at 118.1 C and 468.5 torr, and found to be 2.784 g/L. Calculate KC for the association of the acid.

The amino acid alanine has two isomers, -alanine and -alanine. When equal masses of these two compounds are dissolved in equal amounts of a solvent, the solution of -alanine freezes at the lowest temperature. Which form, -alanine or -alanine, has the larger equilibrium constant for ionization (HXH++X)?

. Under what circumstances can we compare the solubilities of two salts by directly comparing the values of their solubility products?

For the following reactions, predict whether the pressure of the reactants or products increases or remains the same when the volume of the reaction vessel is increased. (a) H2O(l)H2O(g) (b) N2(g)+3H2(g)2NH3(g) (c) C2H4(g)+H2O(g)C2H5OH(g)

What is the law of mass action? Is it true that the value of K depends on the amounts of reactants and products mixed together initially? Explain. Is it true that reactions with large equilibrium constant values are very fast? Explain. There is only one value of the equilibrium constant for a particular system at a particular temperature, but there is an infinite number of equilibrium positions. Explain.

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?