5. Calculate the pH and percent dissociation of a 0.5 Μ HCN solution. (Ka of HCN is 6.2*10^-10 )

Use the same symbols as in Question 61 ( = anion, =OH) for the box below. (a) Fill in a similar box (representing one liter of the same solution) after 2 mol of H+ (2) have been added. Indicate whether the resulting solution is an acid, base, or buffer. (b) Follow the directions of part (a) for the resulting solution after 2 mol of OH- (2 ) have been added. (c) Follow the directions of part (a) for the resulting solution after 5 mol of OH- (5 ) have been added. (Hint: Write the equation for the reaction before you draw the results.)

What is the pH of a solution obtained by mixing 235 mL of NaOH with a pH of 11.57 and 316 mL of Sr(OH)2 with a pH of 12.09? Assume that volumes are additive.

The HCl in a 0.10 M HCl solution is 100% dissociated. What are the molar concentrations of HCl, H3O+, and Cl in the solution?

Novocaine, C13H21O2N2Cl, is the salt of the base procaine and hydrochloric acid. The ionization constant for procaine is 7106. 15 a solution of novocaine acidic or basic? What are [H3O+], [OH-], and pH of a 2.0% solution by mass of novocaine, assuming that the density of the solution is 1.0 g/mL.

Which of the following beakers best represents a container of a weak acid, HA, in water? (Water molecules have been omitted for clarity.)

. Consider 0.25 M solutions of the following salts: NaCl. RbOC1, KI, Ba(ClO4),, and NH4NO3. For each salt, indicate whether the solution is acidic, basic, or neutral.

Each of the following statements concerns a 0.10 M solution of a weak organic base, B. Briefly describe why each statement is either true or false. a [B] is approximately equal to 0.10 M. b [B] is much greater than [HB+]. c [H3O+] is greater than [HB+]. d The pH is 13. e [HB+] is approximately equal to [OH]. f [OH] equals 0.10 M.

Aqueous Solutions of Acids, Bases, and Salts a For each of the following salts, write the reaction that occurs when it dissociates in water: NaCl(s), NaCN(s), KClO2(s), NH4NO3(s), KBr(aq), and NaF(s). b Consider each of the reactions that you wrote above, and identify the aqueous ions that could be proton donors (acids) or proton acceptors (bases). Briefly explain how you decided which ions to choose. c For each of the acids and bases that you identified in pan b, write the chemical reaction it can undergo in aqueous solution (its reaction with water). d Are there any reactions that you have written above that you anticipate will occur to such an extent that the pH of the solution will be affected? As pan of your answer, be sure to explain how you decided. e Assume that in each case above, 0.01 mol of the salt was dissolved in enough water at 25C to make 1.0 L of solution. In each case what additional information would you need in order to calculate the pH? If there are cases where no additional information is required, be sure to state that as well. f Say you take 0.01 mol of NH4CN and dissolve it in enough water at 25C to make 1.0 L of solution. Using chemical reactions and words, explain how you would go about determining what effect this salt will have on the pH of the solution. Be sure to list any additional information you would need to arrive at an answer.

Each box represents an acid solution at equilibrium. Squares represent H+ ions. Circles represent anions. (Although the anions have different identities in each figure, they are all represented as circles.) Water molecules are not shown. Assume that all solutions have the same volume. (a) Which figure represents the strongest acid? (b) Which figure represents the acid with the smallest Ka? (c) Which figure represents the acid with the lowest pH?