Gen Chem II Acid Base Equilibria pH and pOH
34 flashcards covering Gen Chem II Acid Base Equilibria pH and pOH for the GENERAL-CHEMISTRY-2 Gen Chem II Topics section.
Acid-base equilibria, including pH and pOH, are fundamental concepts in General Chemistry II, as outlined by the American Chemical Society (ACS) guidelines. This topic covers the principles of acid and base strength, the calculation of pH and pOH, and the relationship between these two measures. Understanding these concepts is essential for predicting the behavior of chemical reactions in various contexts, including biological systems and industrial processes.
On practice exams and competency assessments, questions about acid-base equilibria often involve calculations requiring the conversion between pH and pOH, as well as determining the concentration of hydrogen or hydroxide ions in a solution. Common traps include confusion between strong and weak acids/bases or miscalculating the logarithmic relationships involved. A frequent oversight is neglecting to consider temperature's effect on pH, which can lead to incorrect conclusions in practical applications.
Terms (34)
- 01
What is the pH of a neutral solution at 25°C?
The pH of a neutral solution at 25°C is 7.0, which indicates equal concentrations of hydrogen ions (H⁺) and hydroxide ions (OH⁻) (Zumdahl, Acid-Base Equilibria chapter).
- 02
How is pH calculated from hydrogen ion concentration?
pH is calculated using the formula pH = -log[H⁺], where [H⁺] is the concentration of hydrogen ions in moles per liter (Tro, Acid-Base Equilibria chapter).
- 03
What is the relationship between pH and pOH?
The relationship is given by the equation pH + pOH = 14 at 25°C, reflecting the inverse relationship between hydrogen and hydroxide ion concentrations (Brown LeMay, Acid-Base Equilibria chapter).
- 04
What is the pOH of a solution with a pH of 9?
The pOH of a solution with a pH of 9 is 5, calculated using the equation pOH = 14 - pH (Tro, Acid-Base Equilibria chapter).
- 05
Define a strong acid in terms of ionization.
A strong acid is one that completely ionizes in solution, resulting in a high concentration of H⁺ ions (Zumdahl, Acid-Base Equilibria chapter).
- 06
What is the pH of a 0.01 M HCl solution?
The pH of a 0.01 M HCl solution is 2, as HCl is a strong acid that completely dissociates, giving [H⁺] = 0.01 M (Brown LeMay, Acid-Base Equilibria chapter).
- 07
How do you find the concentration of H⁺ from pH?
To find the concentration of H⁺ from pH, use the formula [H⁺] = 10^(-pH) (Tro, Acid-Base Equilibria chapter).
- 08
What is the effect of dilution on the pH of a strong acid?
Diluting a strong acid decreases its concentration of H⁺ ions, which increases the pH (Zumdahl, Acid-Base Equilibria chapter).
- 09
What is the pH of a 0.1 M NaOH solution?
The pH of a 0.1 M NaOH solution is 13, as NaOH is a strong base that completely dissociates, resulting in a [OH⁻] of 0.1 M and a corresponding pH (Brown LeMay, Acid-Base Equilibria chapter).
- 10
What is the formula for calculating pOH from hydroxide ion concentration?
pOH is calculated using the formula pOH = -log[OH⁻], where [OH⁻] is the concentration of hydroxide ions (Tro, Acid-Base Equilibria chapter).
- 11
Define a weak acid in terms of ionization.
A weak acid partially ionizes in solution, resulting in an equilibrium between the undissociated acid and its ions (Zumdahl, Acid-Base Equilibria chapter).
- 12
What is the pH of a 0.1 M acetic acid solution?
The pH of a 0.1 M acetic acid solution is approximately 2.87, reflecting its weak acid nature and partial ionization (Brown LeMay, Acid-Base Equilibria chapter).
- 13
How does temperature affect the pH of pure water?
The pH of pure water decreases with increasing temperature due to changes in the ion product of water (Kw) (Tro, Acid-Base Equilibria chapter).
- 14
What is the significance of the pKa value?
The pKa value indicates the strength of an acid; lower pKa values correspond to stronger acids (Brown LeMay, Acid-Base Equilibria chapter).
- 15
How is the pKa related to the Ka of an acid?
pKa is related to the acid dissociation constant (Ka) by the equation pKa = -log(Ka), providing a measure of acid strength (Zumdahl, Acid-Base Equilibria chapter).
- 16
What is the pH of a solution with [H⁺] = 1 x 10⁻⁷ M?
The pH of a solution with [H⁺] = 1 x 10⁻⁷ M is 7, indicating a neutral solution (Tro, Acid-Base Equilibria chapter).
- 17
What is the effect of adding a strong base to a weak acid?
Adding a strong base to a weak acid will shift the equilibrium to the left, decreasing the concentration of H⁺ ions and increasing pH (Brown LeMay, Acid-Base Equilibria chapter).
- 18
How do you calculate the pH of a buffer solution?
The pH of a buffer solution can be calculated using the Henderson-Hasselbalch equation: pH = pKa + log([A⁻]/[HA]) (Tro, Acid-Base Equilibria chapter).
- 19
What happens to the pH when an acid is added to a buffer solution?
When an acid is added to a buffer solution, the pH changes only slightly due to the buffer's ability to neutralize added acid (Brown LeMay, Acid-Base Equilibria chapter).
- 20
What is the pH of a solution at 37°C?
At 37°C, the pH of a neutral solution is approximately 7.4 due to the increase in Kw with temperature (Tro, Acid-Base Equilibria chapter).
- 21
Define the term 'neutralization reaction'.
A neutralization reaction occurs when an acid and a base react to form water and a salt, typically resulting in a pH close to 7 (Brown LeMay, Acid-Base Equilibria chapter).
- 22
What is the pH of a 0.001 M H₂SO₄ solution?
The pH of a 0.001 M H₂SO₄ solution is approximately 2, as H₂SO₄ is a strong acid that dissociates completely in the first step (Zumdahl, Acid-Base Equilibria chapter).
- 23
How do you determine the pH of a mixture of strong and weak acids?
To determine the pH of a mixture of strong and weak acids, the strong acid's contribution to [H⁺] is dominant, and its concentration primarily determines the pH (Tro, Acid-Base Equilibria chapter).
- 24
What is the role of a conjugate base in acid-base reactions?
A conjugate base is the species that remains after an acid donates a proton; it can accept protons in subsequent reactions (Brown LeMay, Acid-Base Equilibria chapter).
- 25
How does the addition of a salt affect the pH of a solution?
The addition of a salt can affect the pH depending on the nature of the ions; salts of strong acids and bases do not affect pH significantly (Tro, Acid-Base Equilibria chapter).
- 26
What is the pH of a saturated solution of NaCl?
The pH of a saturated solution of NaCl is approximately 7, as NaCl does not affect the acidity or basicity of water (Brown LeMay, Acid-Base Equilibria chapter).
- 27
How can you prepare a buffer solution?
A buffer solution can be prepared by mixing a weak acid with its conjugate base or a weak base with its conjugate acid (Tro, Acid-Base Equilibria chapter).
- 28
What is the significance of the buffer capacity?
Buffer capacity refers to the amount of acid or base that a buffer can neutralize without a significant change in pH (Brown LeMay, Acid-Base Equilibria chapter).
- 29
What happens to the pH of a solution when a strong acid is diluted?
Diluting a strong acid increases the pH as the concentration of H⁺ ions decreases (Tro, Acid-Base Equilibria chapter).
- 30
What is the relationship between pH and solubility of salts?
The solubility of certain salts can be affected by pH; for example, the solubility of basic salts increases in acidic solutions (Brown LeMay, Acid-Base Equilibria chapter).
- 31
Define the term 'acid dissociation constant' (Ka).
The acid dissociation constant (Ka) is a quantitative measure of the strength of an acid in solution, defined as the equilibrium constant for the dissociation of the acid (Tro, Acid-Base Equilibria chapter).
- 32
What is the pH of a 0.1 M solution of sodium acetate?
The pH of a 0.1 M solution of sodium acetate can be calculated using the Henderson-Hasselbalch equation, yielding a pH around 9.2 (Brown LeMay, Acid-Base Equilibria chapter).
- 33
How does the common ion effect influence solubility?
The common ion effect decreases the solubility of a salt when a common ion is added to the solution, shifting the equilibrium (Tro, Acid-Base Equilibria chapter).
- 34
What is the pH of a solution with [OH⁻] = 1 x 10⁻⁴ M?
The pH of a solution with [OH⁻] = 1 x 10⁻⁴ M is 10, calculated from pH = 14 - pOH (Brown LeMay, Acid-Base Equilibria chapter).