Chemistry: A Molecular Approach, Chapter 17 - Aqueous Ionic Equilibrium

Flashcards created based on notes from Chapter 17 of Chemistry: A Molecular Approach, focusing on aqueous ionic equilibrium and related concepts.

What is the structure for antifreeze according to the lecture notes?

HOCH2CH2OH

If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.11, what is true about the concentrations of HCHO2 and NaCHO2?

[HCHO2] > [NaCHO2]

If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.89, what is true about the concentrations of HCHO2 and NaCHO2?

[HCHO2] < [NaCHO2]

If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.74, what is true about the concentrations of HCHO2 and NaCHO2?

[HCHO2] = [NaCHO2]

What is the pH of a buffer that is 0.225 M HC2H3O2 and 0.162 M KC2H3O2 if the Ka for HC2H3O2 is 1.8 × 10-5?

4.60

What is the relationship between the concentrations of NH4Cl and NH3 when combining 250.0 mL of 0.15 M NH4Cl with 100.0 mL of 0.20 M NH3?

pH = calculated value will depend on added concentrations.

What is the pH of a solution formed by mixing 250.0 mL of 0.15 M NH4Cl with 200.0 mL of 0.12 M NH3?

9.06

What is the pH of a solution formed by mixing 150.0 mL of 0.10 M HC7H5O2 with 100.0 mL of 0.30 M NaC7H5O2?

4.49

If the Kb for NH3 is 1.8 × 10-5, what is the pH of a solution formed by mixing 100.0 mL of 0.10 M NH3 with 100.0 mL of 0.10 M HNO3?

7.05

In blood, how many times higher is the concentration of bicarbonate compared to carbonic acid?

20

Define buffer capacity.

Buffer capacity is the amount of acid or base that can be added to a buffer without destroying its effectiveness.

Which statement is true regarding the equivalence point during acid-base titration?

The equivalence point is where the amount of acid equals the amount of base during any acid-base titration.

What happens at the equivalence point of a strong monoprotic acid and strong base titration?

The pH will be equal to 7.

For weak monoprotic acid titrated with NaOH at 25°C, what is true at the equivalence point?

The pH will be greater than 7.

How does aluminum hydroxide behave in different pH conditions?

Al(OH)3 is soluble at low pH, insoluble in pH-neutral solution, and soluble at high pH.

What happens to Al(OH)3 in a low pH environment?

Al(H2O)63+ dissolves.

What is true about a good buffer system?

A buffer contains significant amounts of both a weak acid and its conjugate base or weak base and its conjugate acid.

What is the result of adding a strong acid to a buffer solution?

The pH does not change drastically because the strong acid reacts with the conjugate base.

What is the mathematical relationship for an unsaturated solution in comparing Q and Ksp?

Q < Ksp

What is the expression for Kf for Fe(CN)63-?

[Fe3+][CN-]6.

What does the common ion effect imply?

The common ion effect occurs when the solubility of a salt decreases in a solution that already contains one of its constituent ions.