AP Chemistry Flashcards: Molecular Structure Of Acids And Bases

What this deck covers

This deck focuses on Molecular Structure Of Acids And Bases, giving you a quick way to review the definitions, rules, and examples that matter most for AP Chemistry.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Which is the conjugate base of H₂SO₄?

Answer: HSO₄⁻. $H_2SO_4$ loses one proton to form $HSO_4^-$.

Flashcard 2: List one example of a strong acid.

Answer: Hydrochloric acid (HCl). One of the seven common strong acids.

Flashcard 3: What is the Lewis definition of an acid?

Answer: A species that accepts an electron pair. Lewis theory focuses on electron pair interactions, not protons.

Flashcard 4: What is the general formula for calculating pH?

Answer: $pH = -\log[H^+]$. Negative log of hydrogen ion concentration.

Flashcard 5: What is the definition of a Bronsted-Lowry acid?

Answer: A species that donates a proton (H⁺). This is the proton transfer definition used in acid-base chemistry.

Flashcard 6: Identify the conjugate base of HCl.

Answer: Cl⁻. Formed when HCl loses its proton ($H^+$).

Flashcard 7: What is the general formula for calculating pH?

Answer: $pH = -\log[H^+]$. Negative log of hydrogen ion concentration.

Flashcard 8: What is the primary component of stomach acid?

Answer: Hydrochloric acid (HCl). Gastric acid is primarily HCl with pH around 1-2.

Flashcard 9: What is the Henderson-Hasselbalch equation for pOH?

Answer: $pOH = pK_b + \log\left(\frac{[BH⁺]}{[B]}\right)$. Relates buffer pOH to base/acid ratio.

Flashcard 10: What is the definition of a Bronsted-Lowry base?

Answer: A species that accepts a proton (H⁺). This is the proton acceptor definition in Bronsted-Lowry theory.

Flashcard 11: What does a small $K_a$ value indicate about an acid?

Answer: The acid is weak, dissociating less in solution. Small $K_a$ means lower ionization tendency.

Flashcard 12: What is the effect of dilution on the pH of a buffer?

Answer: Minimal change in pH. Buffer capacity maintains pH despite concentration changes.

Flashcard 13: Identify the Lewis acid in AlCl₃ + Cl⁻ → AlCl₄⁻.

Answer: AlCl₃. $AlCl_3$ accepts the electron pair from $Cl^-$.

Flashcard 14: Define the term 'amphoteric'.

Answer: A species that can act as both an acid and a base. Can donate or accept protons depending on conditions.

Flashcard 15: Which is stronger: HCl or HF?

Answer: HCl. HCl is a strong acid; HF is weak.

Flashcard 16: State the relationship between $K_a$ and $K_b$ for conjugate pairs.

Answer: $K_a \times K_b = K_w$. This relationship connects conjugate acid-base pairs.

Flashcard 17: What does a large $K_a$ value indicate about an acid?

Answer: The acid is strong, dissociating more in solution. Large $K_a$ means greater ionization tendency.

Flashcard 18: What does a small $K_a$ value indicate about an acid?

Answer: The acid is weak, dissociating less in solution. Small $K_a$ means lower ionization tendency.

Flashcard 19: What is the Lewis definition of an acid?

Answer: A species that accepts an electron pair. Lewis theory focuses on electron pair interactions, not protons.

Flashcard 20: Identify the conjugate base of HCl.

Answer: Cl⁻. Formed when HCl loses its proton ($H^+$).

Flashcard 21: Identify the Lewis base in NH₃ + BF₃ → NH₃BF₃.

Answer: NH₃. $NH_3$ donates its lone pair to $BF_3$.

Flashcard 22: What is a buffer solution?

Answer: A solution that resists changes in pH when acids or bases are added. Contains weak acid/base and conjugate pairs.

Flashcard 23: What is the definition of a Bronsted-Lowry base?

Answer: A species that accepts a proton (H⁺). This is the proton acceptor definition in Bronsted-Lowry theory.

Flashcard 24: List one example of a strong base.

Answer: Sodium hydroxide (NaOH). One of the common strong bases.

Flashcard 25: Which is the conjugate base of H₂SO₄?

Answer: HSO₄⁻. $H_2SO_4$ loses one proton to form $HSO_4^-$.

Flashcard 26: What is the Lewis definition of an acid?

Answer: A species that accepts an electron pair. Lewis theory focuses on electron pair interactions, not protons.

Flashcard 27: List one example of a weak base.

Answer: Ammonia (NH₃). A common weak base that accepts protons from water.

Flashcard 28: List one example of a weak base.

Answer: Ammonia (NH₃). A common weak base that accepts protons from water.

Flashcard 29: What is the formula for calculating pOH?

Answer: $pOH = -\log[OH⁻]$. Negative log of hydroxide ion concentration.

Flashcard 30: Which is stronger: HCl or HF?

Answer: HCl. HCl is a strong acid; HF is weak.

Flashcard 31: What is the Henderson-Hasselbalch equation for pH?

Answer: $pH = pK_a + \log\left(\frac{[A⁻]}{[HA]}\right)$. Relates buffer pH to acid/base ratio.

Flashcard 32: What is the common ion effect?

Answer: The shift in equilibrium due to the addition of a common ion. Suppresses ionization of weak acids or bases.

Flashcard 33: What is the definition of a Bronsted-Lowry base?

Answer: A species that accepts a proton (H⁺). This is the proton acceptor definition in Bronsted-Lowry theory.

Flashcard 34: Define the term 'weak acid'.

Answer: An acid that partially dissociates in solution. Only a small percentage ionizes in aqueous solution.

Flashcard 35: Define the term 'weak acid'.

Answer: An acid that partially dissociates in solution. Only a small percentage ionizes in aqueous solution.

Flashcard 36: What does a small $K_a$ value indicate about an acid?

Answer: The acid is weak, dissociating less in solution. Small $K_a$ means lower ionization tendency.

Flashcard 37: What is the Henderson-Hasselbalch equation for pOH?

Answer: $pOH = pK_b + \log\left(\frac{[BH^+]}{[B]}\right)$. Relates buffer pOH to base/acid ratio.

Flashcard 38: Identify the Lewis acid in AlCl₃ + Cl⁻ → AlCl₄⁻.

Answer: AlCl₃. $AlCl_3$ accepts the electron pair from $Cl^-$.

Flashcard 39: Identify an example of an amphoteric substance.

Answer: Water (H₂O). Can act as acid or base in different reactions.

Flashcard 40: Identify the Lewis base in NH₃ + BF₃ → NH₃BF₃.

Answer: NH₃. $NH_3$ donates its lone pair to $BF_3$.

Flashcard 41: Identify the conjugate base of HCl.

Answer: Cl⁻. Formed when HCl loses its proton ($H^+$).

Flashcard 42: What does a large $K_a$ value indicate about an acid?

Answer: The acid is strong, dissociating more in solution. Large $K_a$ means greater ionization tendency.

Flashcard 43: Define the term 'strong base'.

Answer: A base that completely dissociates in solution. Nearly 100% ionization occurs in aqueous solution.

Flashcard 44: Which is stronger: HCl or HF?

Answer: HCl. HCl is a strong acid; HF is weak.

Flashcard 45: Identify the common ion in a mixture of HCl and NaCl.

Answer: Cl⁻. Both compounds contain chloride ions.

Flashcard 46: What is the pH of a solution with $[H⁺] = 1 \times 10^{-3}$ M?

Answer:

1. Using $pH = -\log(1 \times 10^{-3}) = 3$.

Flashcard 47: Identify an example of an amphoteric substance.

Answer: Water (H₂O). Can act as acid or base in different reactions.

Flashcard 48: State the relationship between pH and pOH.

Answer: $pH + pOH = 14$. This relationship holds at 25°C due to $K_w$.

Flashcard 49: What is the Lewis definition of a base?

Answer: A species that donates an electron pair. Lewis bases are electron pair donors in chemical reactions.

Flashcard 50: Define the term 'amphoteric'.

Answer: A species that can act as both an acid and a base. Can donate or accept protons depending on conditions.

Flashcard 51: List one example of a weak base.

Answer: Ammonia (NH₃). A common weak base that accepts protons from water.

Flashcard 52: Define the term 'strong acid'.

Answer: An acid that completely dissociates in solution. Nearly 100% ionization occurs in aqueous solution.

Flashcard 53: Identify the Lewis base in NH₃ + BF₃ → NH₃BF₃.

Answer: NH₃. $NH_3$ donates its lone pair to $BF_3$.

Flashcard 54: Identify the Lewis acid in AlCl₃ + Cl⁻ → AlCl₄⁻.

Answer: AlCl₃. $AlCl_3$ accepts the electron pair from $Cl^-$.

Flashcard 55: What is the Lewis definition of a base?

Answer: A species that donates an electron pair. Lewis bases are electron pair donors in chemical reactions.

Flashcard 56: What does a large $K_a$ value indicate about an acid?

Answer: The acid is strong, dissociating more in solution. Large $K_a$ means greater ionization tendency.

Flashcard 57: What is the pH of a buffer with equal concentrations of acid and base?

Answer: pH = pK_a. When $\log(1) = 0$, so pH equals $pK_a$.

Flashcard 58: What is the pOH of a solution with $[OH⁻] = 1 \times 10^{-5}$ M?

Answer:

1. Using $pOH = -\log(1 \times 10^{-5}) = 5$.

Flashcard 59: What is the primary component of stomach acid?

Answer: Hydrochloric acid (HCl). Gastric acid is primarily HCl with pH around 1-2.

Flashcard 60: What is the Henderson-Hasselbalch equation for pH?

Answer: $pH = pK_a + \log\left(\frac{[A⁻]}{[HA]}\right)$. Relates buffer pH to acid/base ratio.

Flashcard 61: What is the effect of dilution on the pH of a buffer?

Answer: Minimal change in pH. Buffer capacity maintains pH despite concentration changes.

Flashcard 62: What is a buffer solution?

Answer: A solution that resists changes in pH when acids or bases are added. Contains weak acid/base and conjugate pairs.

Flashcard 63: What is the formula for the base dissociation constant, $K_b$?

Answer: $K_b = \frac{[BH^+][OH^-]}{[B]}$. Measures the extent of base dissociation in solution.

Flashcard 64: Define the term 'amphoteric'.

Answer: A species that can act as both an acid and a base. Can donate or accept protons depending on conditions.

Flashcard 65: What is the pH of a buffer with equal concentrations of acid and base?

Answer: pH = pK_a. When $\log(1) = 0$, so pH equals $pK_a$.

Flashcard 66: List one example of a strong acid.

Answer: Hydrochloric acid (HCl). One of the seven common strong acids.

Flashcard 67: What is the formula for calculating pOH?

Answer: $pOH = -\log[OH^{-}]$. Negative log of hydroxide ion concentration.

Flashcard 68: What is the primary component of stomach acid?

Answer: Hydrochloric acid (HCl). Gastric acid is primarily HCl with pH around 1-2.

Flashcard 69: State the relationship between $K_a$ and $K_b$ for conjugate pairs.

Answer: $K_a \times K_b = K_w$. This relationship connects conjugate acid-base pairs.

Flashcard 70: What is the formula for the base dissociation constant, $K_b$?

Answer: $K_b = \frac{[BH⁺][OH⁻]}{[B]}$. Measures the extent of base dissociation in solution.

Flashcard 71: What is the Henderson-Hasselbalch equation for pOH?

Answer: $pOH = pK_b + \log\left(\frac{[BH⁺]}{[B]}\right)$. Relates buffer pOH to base/acid ratio.

Flashcard 72: What is the general formula for calculating pH?

Answer: $pH = -\log[H⁺]$. Negative log of hydrogen ion concentration.

Flashcard 73: What is a buffer solution?

Answer: A solution that resists changes in pH when acids or bases are added. Contains weak acid/base and conjugate pairs.

Flashcard 74: Define the term 'strong base'.

Answer: A base that completely dissociates in solution. Nearly 100% ionization occurs in aqueous solution.

Flashcard 75: State the relationship between $K_a$ and $K_b$ for conjugate pairs.

Answer: $K_a \times K_b = K_w$. This relationship connects conjugate acid-base pairs.

Flashcard 76: Define the term 'strong acid'.

Answer: An acid that completely dissociates in solution. Nearly 100% ionization occurs in aqueous solution.

Flashcard 77: What is the effect of dilution on the pH of a buffer?

Answer: Minimal change in pH. Buffer capacity maintains pH despite concentration changes.

Flashcard 78: What is the Lewis definition of a base?

Answer: A species that donates an electron pair. Lewis bases are electron pair donors in chemical reactions.

Flashcard 79: What is the pH of a solution with $[H⁺] = 1 \times 10^{-3}$ M?

Answer:

1. Using $pH = -\log(1 \times 10^{-3}) = 3$.

Flashcard 80: Identify an example of an amphoteric substance.

Answer: Water (H₂O). Can act as acid or base in different reactions.

Flashcard 81: Identify the common ion in a mixture of HCl and NaCl.

Answer: Cl⁻. Both compounds contain chloride ions.

Flashcard 82: What is the common ion effect?

Answer: The shift in equilibrium due to the addition of a common ion. Suppresses ionization of weak acids or bases.

Flashcard 83: Identify the conjugate acid of NH₃.

Answer: NH₄⁺. Formed when $NH_3$ gains a proton ($H^+$).

Flashcard 84: Define the term 'strong acid'.

Answer: An acid that completely dissociates in solution. Nearly 100% ionization occurs in aqueous solution.

Flashcard 85: List one example of a weak acid.

Answer: Acetic acid (CH₃COOH). A common weak acid found in vinegar.

Flashcard 86: Define the term 'strong base'.

Answer: A base that completely dissociates in solution. Nearly 100% ionization occurs in aqueous solution.

Flashcard 87: What is the pH of a buffer with equal concentrations of acid and base?

Answer: pH = pK_a. When $\log(1) = 0$, so pH equals $pK_a$.

Flashcard 88: State the relationship between pH and pOH.

Answer: $pH + pOH = 14$. This relationship holds at 25°C due to $K_w$.

Flashcard 89: Define the term 'weak base'.

Answer: A base that partially dissociates in solution. Only a small percentage ionizes in aqueous solution.

Flashcard 90: State the relationship between pH and pOH.

Answer: $pH + pOH = 14$. This relationship holds at 25°C due to $K_w$.

Flashcard 91: Define the term 'weak base'.

Answer: A base that partially dissociates in solution. Only a small percentage ionizes in aqueous solution.

Flashcard 92: Identify the common ion in a mixture of HCl and NaCl.

Answer: Cl⁻. Both compounds contain chloride ions.

Flashcard 93: Which is the conjugate base of H₂SO₄?

Answer: HSO₄⁻. $H_2SO_4$ loses one proton to form $HSO_4^-$.

Flashcard 94: What is the definition of a Bronsted-Lowry acid?

Answer: A species that donates a proton (H⁺). This is the proton transfer definition used in acid-base chemistry.

Flashcard 95: Define the term 'weak acid'.

Answer: An acid that partially dissociates in solution. Only a small percentage ionizes in aqueous solution.

Flashcard 96: What is the pH of a solution with $[H⁺] = 1 \times 10^{-3}$ M?

Answer:

1. Using $pH = -\log(1 \times 10^{-3}) = 3$.

Flashcard 97: What is the formula for the base dissociation constant, $K_b$?

Answer: $K_b = \frac{[BH⁺][OH⁻]}{[B]}$. Measures the extent of base dissociation in solution.

Flashcard 98: Define the term 'weak base'.

Answer: A base that partially dissociates in solution. Only a small percentage ionizes in aqueous solution.

Flashcard 99: What is the value of $K_w$ at 25°C?

Answer: $1.0 \times 10^{-14}$. The ion product constant for water at standard temperature.

Flashcard 100: What is the pOH of a solution with $[OH⁻] = 1 \times 10^{-5}$ M?

Answer:

1. Using $pOH = -\log(1 \times 10^{-5}) = 5$.