The preparations of two aqueous solutions are described in the table below. For each solution, write the chemical formulas of the major species present at equilibrium. You can leave out water itself. Write the chemical formulas of the species that will act as acids in the 'acids' row, the formulas of the species that will act as bases in the 'bases' row, and the formulas of the species that will act as neither acids nor bases in the 'other' row. You will find it useful to keep in mind that HCN is a weak acid. acids: ☐ 0.07 mol of NaOH is added to 1.0 L of a 0.5 M HCN solution. bases: ☐ X other: ☐ 0.2 mol of KOH is added to 1.0 L of a solution that is 0.5 M in both HCN and KCN. ☐ ☐ ☐ acids: ☐ bases: ☐ other: ☐ 0.0.... G

Write equations to illustrate the acid-base reaction when each of the following pairs of Brnsted acids and bases are combined: Acid Base a.HOCl H2O b.HClO4 NH3 c.H2O NH2 d.H2O OCl e.HC2O4 H2O

When perchloric acid ionizes, it makes the perchlorate ion, ClO4. Draw the Lewis electron dot symbol for the perchlorate ion.

Aluminum chloride, AlCl3, reacts with trimethyl-amine, N(CH3)3. What would you guess to be the product of this reaction? Explain why you think so. Describe the reaction in terms of one of the acid base concepts. Write an appropriate equation to go with this description. Which substance is the acid according to this acidbase concept? Explain.

How would you compare the strengths of two weak acids experimentally? By looking up information in a table or a handbook?

Classify each of the following statements as true or false: aAll Brnsted-Lowry acids are Arrhenius acids. bAll Arrhenius bases are Brnsted-Lowry bases, but not all Brnsted-Lowry bases are Arrhenius bases. c HCO3 is capable of being amphoteric. d HS is the conjugate base of S2. eIf the species on the right side of an ionization equilibrium are present in greater abundance than those on the left, the equilibrium is favored in the forward direction. f NH4+ cannot act as a Lewis base. gWeak bases have a weak attraction for protons. hThe stronger acid and the stronger base are always on the same side of a proton transfer reaction equation. iA proton transfer reaction is always favored in the direction that yields the stronger acid. jA solution with pH=9 is more acidic than one with pH=4. kA solution with pH=3 is twice as acidic as one with pH=6. lA pOH of 4.65 expresses the hydroxide ion concentration of a solution in three significant figures.

The dihydrogen phosphate ion has the ability to act as an acid in the presence of a base and as a base in the presence of an acid. What is this property called? Illustrate this behavior with water by writing BrnstedLowry acidbase reactions. Also illustrate this property by selecting a common acid and base to react with the dihydrogen phosphate ion.

Explain why equilibrium arrows are used in the ionization equations for some acids.