Determine the pH of a 0.45 M NH 4NO 3 solution at 25°C. The Kb for NH 3 is 1.76 x 10 5. A. 4.73 B. 11.52 C. 4.50 D. 4.80 E. 9.27

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 pH of Mixtures of Acid, Base, and Salt Solutions a When 0.10 mol of the ionic solid NaX, where X is an unknown anion, is dissolved in enough water to make 1.0 L of solution, the pH of the solution is 9.12. When 0.10 mol of the ionic solid ACl, where A is an unknown cation, is dissolved in enough water to make 1.0 L of solution, the pH of the solution is 7.00. What would be the pH of 1.0 L of solution that contained 0.10 mol of AX? Be sure to document how you arrived at your answer. b In the AX solution prepared above, is there any OH present? If so, compare the [OH] in the solution to the [H3O+]. c From the information presented in part a, calculate Kb for the X(aq) anion and Ka for the conjugate acid of X(aq). d To 1.0 L of solution that contains 0.10 mol of AX, you add 0.025 mol of HCl. How will the pH of this solution compare to that of the solution that contained only NaX? Use chemical reactions as part of your explanation; you do not need to solve for a numerical answer. e Another 1.0 L sample of solution is prepared by mixing 0.10 mol of AX and 0.10 mol of HCl. The pH of the resulting solution is found to be 3.12. Explain why the pH of this solution is 3.12. f Finally, consider a different 1.0-L sample of solution that contains 0.10 mol of AX and 0.1 mol of NaOH. The pH of this solution is found to be 13.00. Explain why the pH of this solution is 13.00. g Some students mistakenly think that a solution that contains 0.10 mol of AX and 0.10 mol of HCl should have a pH of 1.00. Can you come up with a reason why students have this misconception? Write an approach that you would use to help these students understand what they are doing wrong.

Ionization of the first proton from H2SeO4 is complete (H2SeO4 is a strong acid); the acid-ionization constant for the second proton is 1.2 102. a What would be the approximate hydronium-ion concentration in 0.150 M H2SeO4 if ionization of the second proton were ignored? b The ionization of the second proton must be considered for a more exact answer, however. Calculate the hydronium-ion concentration in 0.150 M H2SeO4, accounting for the ionization of both protons.

A quantity of 0.25 M sodium hydroxide is added to a solution containing 0.15 mol of acetic acid. The final volume of the solution is 375 mL and the pH of this solution is 4.45. a What is the molar concentration of the sodium acetate? b How many milliliters of sodium hydroxide were added to the original solution? c What was the original concentration of the acetic acid?

Tile pH of a solution of household ammonia, a 0.950 M solution of NH3 is 11.612. Determine Kb for NH3 from these data.

The pH of a household cleaning solution is 11.50. This cleanser is an aqueous solution of ammonia with a density of 1.00 g/mL. What is the mass percentage of ammonia in the solution?

The pH of a 0.20-M solution of HP is 1.92. Determine Ka far HF from these data.

A solution of acetic acid, HC2H3O2, on a laboratory shelf was of undetermined concentration. If the pH of the solution was found to be 2.57, what was the concentration of the acetic acid? The Ka of acetic acid is 1.7 105.

What is a salt? List some anions that behave as weak bases in water. List some anions that have no basic properties in water. List some cations that behave as weak acids in water. List some cations that have no acidic properties in water. Using these lists, give some formulas for salts that have only weak base properties in water. What strategy would you use to solve for the pH of these basic salt solutions? Identify some salts that have only weak acid properties in water. What strategy would you use to solve for the pH of these acidic salt solutions? Identify some salts that have no acidic or basic properties in water (produce neutral solutions). When a salt contains both a weak acid ion and a weak base ion, how do you predict whether the solution pH is acidic, basic, or neutral?