Chapter 17

Select the statements that correctly describe how to calculate the pH at various points during the titration of a weak acid against a strong base.

-All the equivalence point the pH calculation is based on the reaction of the conjugate base A- with H2O -The initial [H3O+] is calculated from [HA] and Ka.

Which of the following options correctly describe how to calculate the pH at various stages during the titration of a strong acid against a strong base?

-At the equivalence point pH=7.00 -Initial pH=-log[HA]

Which of the following statements correctly describe a strong acid- weak base titration curve?

-Before the equivalence point is reached, the weak base and its conjugate acid are both present in solution. -The pH at the equivalence point its < 7.00

What factors exist the solubility of ionic compounds?

-Common ion effect - pH - Formation of complex

Which of the following quantities must be known in order to calculate the pH of an acid-base buffer solution using the Henderson-Hasselbalch equation?

-Ka of weak acid or Kb of weak base -Concentration of conjugate base - Concentration of weak base

Which of the following combinations could be used in an acid- base buffer system?

-NH3/ NH4Cl -HNO2/ KNO2 -CH3COOH/ NaCH3COO-

Why does the equivalence point for a weak base- strong acid titration occur at a pH < 7.00?

-The conjugate acid of the weak base reacts with H2O to give a solution with pH < 7.00

Which of the following statements correctly describe the titration curve for the titration of a strong acid with a strong base?

-The pH rise is very steep close to the equivalence point of the titration. -the equivalence point is at a pH of 7.00

When comparing the titration curve for a weak acid- strong base titration and a strong acid- strong base titration the following differences are found.

-the curve for the weak acid- strong base titration rises gradually before the steep rise to the equivalence point. -the pH at the equivalence point is about 7.00 for the weak acid- strong base titration.

In order for a solution of a weak acid and its conjugate base to be considered a buffer, the ratio of base concentration to acid concentration must be within the range _______________

0.1 < [base]/[acid] < 10

_____________ is the number of grams of solute in 1 L of a saturated solution (mol/L)

Molar solubility

______________ involves the principle of selective precipitation and can be used to identify the types of ions present in a solution.

Qualitative analysis

____________ is the number of grams of solute in 1 L of a saturated solution (g/L)

Solubility

For a weak acid that has dissolved in water, the ionization equilibrium will shift toward the reactants if a quantity of the conjugate base is added to the solution. this is known as the _______________________

common ion effect

The __________________ of a titration is the point at which the color of the indicator changes.

endpoint

Compared to a strong acid- strong base titration, the curve for a weak acid- strong base titration begins at a ___________ pH, and has a ____________ vertical section as the equivalence point is reached.

higher, smaller

When a strong acid or base is added to a buffer system there is a __________ change in the [HA]/[A] ratio and thus a ___________ change in pH.

smaller, smaller

An indicator is a(n) ________________ organic acid that has a different color than its ___________ base. Each indicator changes color over a specific ____ range.

weak, conjugate, pH