AP Chemistry Flashcards: Acid Base Titrations

What this deck covers

This deck focuses on Acid Base Titrations, 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 option describes a buffer solution?

Answer: Resists changes in pH upon addition of acid or base. Contains conjugate acid-base pair to maintain pH stability.

Flashcard 2: What is the equivalence point in a titration curve?

Answer: Where moles of acid equal moles of base. Stoichiometric neutralization point on titration curve.

Flashcard 3: What is a standard solution?

Answer: A solution of known concentration. Precisely known concentration for quantitative analysis.

Flashcard 4: What is the relationship between $K_a$, the acid dissociation constant, and acid strength?

Answer: Higher $K_a$ indicates a stronger acid. Larger $K_a$ means greater ionization and stronger acid.

Flashcard 5: Calculate the pH of a 0.01 M HCl solution.

Answer: pH = 2. Strong acid: pH = $-\log(0.01) = -\log(10^{-2}) = 2$.

Flashcard 6: What is the pH of a neutral solution at 25°C?

Answer: $pH = 7$. Equal concentrations of $H^+$ and $OH^-$ at 25°C.

Flashcard 7: Calculate the moles of HCl in 25 mL of 0.1 M solution.

Answer: 0.0025 moles. Convert volume to L (0.025 L), multiply by molarity (0.1 M).

Flashcard 8: Choose the correct pH range for phenolphthalein.

Answer: 8.2 to 10.0. Indicator's transition range for color change.

Flashcard 9: What is the pH of a 0.1 M NH₃ solution if $K_b = 1.8 \times 10^{-5}$?

Answer: pH ≈ 11.1. Use $K_b$ expression: $[OH^-] = \sqrt{K_b \times C}$ then find pH.

Flashcard 10: Calculate the volume of 0.1 M NaOH needed to neutralize 50 mL of 0.1 M HCl.

Answer: 50 mL. Equal molarity and volume means 1:1 mole ratio requires equal volume.

Flashcard 11: Identify the formula to convert pOH to hydroxide ion concentration.

Answer: $[\text{OH}^{-}] = 10^{-\text{pOH}}$. Inverse relationship: pOH is negative log of $[OH^-]$.

Flashcard 12: Which indicator is commonly used for strong acid-strong base titrations?

Answer: Phenolphthalein. Changes color at pH 8.2-10, ideal for strong acid-base endpoints.

Flashcard 13: Calculate the pH of a 0.01 M HCl solution.

Answer: pH = 2. Strong acid: pH = $-\log(0.01) = -\log(10^{-2}) = 2$.

Flashcard 14: State the formula for converting pH to hydrogen ion concentration.

Answer: $[\text{H}^+] = 10^{-\text{pH}}$. Inverse relationship: pH is negative log of $[H^+]$.

Flashcard 15: Calculate the pOH of a 0.01 M NaOH solution.

Answer: pOH = 2. Strong base: pOH = $-\log(0.01) = 2$.

Flashcard 16: In a titration, what is the titrant?

Answer: The solution added from the burette. Standard solution delivered from burette during analysis.

Flashcard 17: Which option best describes a titration curve?

Answer: Graph of pH versus volume of titrant added. Visual representation showing pH changes during titration process.

Flashcard 18: Find and correct the error: 'The equivalence point is always at pH 7.'

Answer: Not always; depends on the strength of acid and base. Only true for strong acid-strong base; weak acids/bases differ.

Flashcard 19: What is the color change of phenolphthalein in basic solutions?

Answer: Colorless to pink. Phenolphthalein is colorless in acid, pink in base.

Flashcard 20: Determine the pH of a solution with $[\text{H}^+] = 10^{-6}$ M.

Answer: pH = 6. pH is defined as $-\log[H^+] = -\log(10^{-6}) = 6$.

Flashcard 21: Identify the primary characteristic of a weak acid.

Answer: Partially ionizes in solution. Incomplete dissociation results in equilibrium with undissociated acid.

Flashcard 22: What is the role of a pipette in a titration?

Answer: To measure and transfer a specific volume of solution. Precision instrument for accurate volume transfer.

Flashcard 23: In a titration, what is the titrant?

Answer: The solution added from the burette. Standard solution delivered from burette during analysis.

Flashcard 24: What is the purpose of a titration in acid-base chemistry?

Answer: To determine the concentration of an unknown solution. Uses known titrant to find unknown concentration via stoichiometry.

Flashcard 25: Which equation relates pH and pOH?

Answer: $\text{pH} + \text{pOH} = 14$. Fundamental relationship for aqueous solutions at 25°C.

Flashcard 26: Calculate the volume of 0.1 M NaOH needed to neutralize 50 mL of 0.1 M HCl.

Answer: 50 mL. Equal molarity and volume means 1:1 mole ratio requires equal volume.

Flashcard 27: State the formula for calculating molarity.

Answer: $M = \frac{\text{moles of solute}}{\text{liters of solution}}$. Defines concentration as moles of solute per liter of solution.

Flashcard 28: State the formula for converting pH to hydrogen ion concentration.

Answer: $[\text{H}^+] = 10^{-\text{pH}}$. Inverse relationship: pH is negative log of $[H^+]$

Flashcard 29: What is the definition of a titrant?

Answer: A solution of known concentration used in titration. Standard solution added from burette to determine analyte concentration.

Flashcard 30: What is the purpose of a titration in acid-base chemistry?

Answer: To determine the concentration of an unknown solution. Uses known titrant to find unknown concentration via stoichiometry.

Flashcard 31: Which option best describes a titration curve?

Answer: Graph of pH versus volume of titrant added. Visual representation showing pH changes during titration process.

Flashcard 32: Identify the primary purpose of an indicator in a titration.

Answer: To signal the endpoint of the titration. Color change marks approximate equivalence point.

Flashcard 33: What is the endpoint of a titration?

Answer: The point where the indicator changes color. Observable color change indicating approximate equivalence point.

Flashcard 34: Identify the endpoint in a titration.

Answer: The point at which the indicator changes color. Visual signal used to determine when to stop adding titrant.

Flashcard 35: What is the effect of a strong base on the pH of a buffer?

Answer: Slight increase in pH. Buffer components consume added base, minimizing pH change.

Flashcard 36: What is the effect of dilution on the pH of a strong acid?

Answer: Increases the pH. Dilution decreases $[H^+]$, raising pH toward neutral.

Flashcard 37: What happens to pH when a strong acid is added to a buffer?

Answer: Slight decrease in pH. Buffer components consume added acid, minimizing pH change.

Flashcard 38: What happens to pH when a strong acid is added to a buffer?

Answer: Slight decrease in pH. Buffer components consume added acid, minimizing pH change.

Flashcard 39: Which term describes the solution whose concentration is to be determined during titration?

Answer: Analyte. The unknown solution whose concentration is being determined.

Flashcard 40: State the formula for calculating molarity.

Answer: $M = \frac{\text{moles of solute}}{\text{liters of solution}}$. Defines concentration as moles of solute per liter of solution.

Flashcard 41: Which acid-base pair has a higher pH at the equivalence point: strong acid-weak base or weak acid-strong base?

Answer: Weak acid-strong base. Weak acid-strong base gives basic equivalence point (pH > 7).

Flashcard 42: What is the primary characteristic of a strong acid?

Answer: Completely ionizes in solution. Dissociates nearly 100% in aqueous solution.

Flashcard 43: Which acid-base pair has a higher pH at the equivalence point: strong acid-weak base or weak acid-strong base?

Answer: Weak acid-strong base. Weak acid-strong base gives basic equivalence point (pH > 7).

Flashcard 44: Calculate the moles of HCl in 25 mL of 0.1 M solution.

Answer: 0.0025 moles. Convert volume to L (0.025 L), multiply by molarity (0.1 M).

Flashcard 45: What type of reaction occurs during a titration?

Answer: Neutralization. Acid and base react to form salt and water.

Flashcard 46: What is the role of a pipette in a titration?

Answer: To measure and transfer a specific volume of solution. Precision instrument for accurate volume transfer.

Flashcard 47: Which term describes the solution whose concentration is to be determined during titration?

Answer: Analyte. The unknown solution whose concentration is being determined.

Flashcard 48: What is the role of a burette in a titration?

Answer: To deliver a precise volume of titrant. Graduated tube allows controlled addition and volume measurement.

Flashcard 49: What is the pH at the equivalence point for a strong acid-strong base titration?

Answer: pH = 7. Equal amounts of strong acid and base neutralize to neutral pH.

Flashcard 50: Identify the endpoint in a titration.

Answer: The point at which the indicator changes color. Visual signal used to determine when to stop adding titrant.

Flashcard 51: Find the pH of a solution with $[\text{OH}^-] = 10^{-3}$ M.

Answer: pH = 11. pOH = $-\log(10^{-3}) = 3$, so pH = $14 - 3 = 11$.

Flashcard 52: What is the pH at the equivalence point for a strong acid-strong base titration?

Answer: pH = 7. Equal amounts of strong acid and base neutralize to neutral pH.

Flashcard 53: What is the role of a burette in a titration?

Answer: To deliver a precise volume of titrant. Graduated tube allows controlled addition and volume measurement.

Flashcard 54: What is the pH of a 0.1 M NH₃ solution if $K_b = 1.8 \times 10^{-5}$?

Answer: pH ≈ 11.1. Use $K_b$ expression: $[OH^-] = \sqrt{K_b \times C}$ then find pH.

Flashcard 55: Which indicator is commonly used for strong acid-strong base titrations?

Answer: Phenolphthalein. Changes color at pH 8.2-10, ideal for strong acid-base endpoints.

Flashcard 56: Which equation relates pH and pOH?

Answer: $\text{pH} + \text{pOH} = 14$. Fundamental relationship for aqueous solutions at 25°C.

Flashcard 57: What is the effect of dilution on the pH of a strong acid?

Answer: Increases the pH. Dilution decreases $[H^+]$, raising pH toward neutral.

Flashcard 58: Find and correct the error: 'The equivalence point is always at pH 7.'

Answer: Not always; depends on the strength of acid and base. Only true for strong acid-strong base; weak acids/bases differ.

Flashcard 59: What is the primary characteristic of a strong acid?

Answer: Completely ionizes in solution. Dissociates nearly 100% in aqueous solution.

Flashcard 60: What is the endpoint of a titration?

Answer: The point where the indicator changes color. Observable color change indicating approximate equivalence point.

Flashcard 61: What is the definition of a titrant?

Answer: A solution of known concentration used in titration. Standard solution added from burette to determine analyte concentration.

Flashcard 62: What is a standard solution?

Answer: A solution of known concentration. Precisely known concentration for quantitative analysis.

Flashcard 63: Which option describes a buffer solution?

Answer: Resists changes in pH upon addition of acid or base. Contains conjugate acid-base pair to maintain pH stability.

Flashcard 64: Determine the pH of a solution with $[\text{H}^+] = 10^{-6}$ M.

Answer: pH = 6. pH is defined as $-\log[H^+] = -\log(10^{-6}) = 6$.

Flashcard 65: What type of reaction occurs during a titration?

Answer: Neutralization. Acid and base react to form salt and water.

Flashcard 66: What is the color change of phenolphthalein in basic solutions?

Answer: Colorless to pink. Phenolphthalein is colorless in acid, pink in base.

Flashcard 67: What is the equivalence point in a titration curve?

Answer: Where moles of acid equal moles of base. Stoichiometric neutralization point on titration curve.

Flashcard 68: Identify the formula to convert pOH to hydroxide ion concentration.

Answer: $[\text{OH}^-] = 10^{-\text{pOH}}$. Inverse relationship: pOH is negative log of $[OH^-]$.

Flashcard 69: What is the relationship between $K_a$, the acid dissociation constant, and acid strength?

Answer: Higher $K_a$ indicates a stronger acid. Larger $K_a$ means greater ionization and stronger acid.

Flashcard 70: Choose the correct pH range for phenolphthalein.

Answer: 8.2 to 10.0. Indicator's transition range for color change.

Flashcard 71: Identify the primary purpose of an indicator in a titration.

Answer: To signal the endpoint of the titration. Color change marks approximate equivalence point.

Flashcard 72: What is the effect of a strong base on the pH of a buffer?

Answer: Slight increase in pH. Buffer components consume added base, minimizing pH change.

Flashcard 73: State the formula to find pOH from hydroxide ion concentration.

Answer: $\text{pOH} = -\text{log}[\text{OH}^-]$. Negative logarithm relationship for hydroxide concentration.

Flashcard 74: Find the pH of a solution with $[\text{OH}^-] = 10^{-3}$ M.

Answer: pH = 11. pOH = $-\log(10^{-3}) = 3$, so pH = $14 - 3 = 11$.

Flashcard 75: State the formula to find pOH from hydroxide ion concentration.

Answer: $\mathrm{pOH} = -\log [\mathrm{OH}^{-}]$. Negative logarithm relationship for hydroxide concentration.

Flashcard 76: Identify the primary characteristic of a weak acid.

Answer: Partially ionizes in solution. Incomplete dissociation results in equilibrium with undissociated acid.

Flashcard 77: Calculate the pOH of a 0.01 M NaOH solution.

Answer: pOH = 2. Strong base: pOH = $-\log(0.01) = 2$.