AP Chemistry Questions on Strong Acids and Bases

📚 Quick Study Guide

• ⚗️ Strong Acids: Completely dissociate in water, meaning they donate all their protons ($H^+$). Common examples include hydrochloric acid ($HCl$), sulfuric acid ($H_2SO_4$), and nitric acid ($HNO_3$).
• 💧 Strong Bases: Completely dissociate in water to produce hydroxide ions ($OH^-$). Common examples include sodium hydroxide ($NaOH$) and potassium hydroxide ($KOH$).
• ⚖️ pH Scale: Measures the acidity or basicity of a solution. pH = $-log[H^+]$. A pH less than 7 indicates an acidic solution, pH greater than 7 indicates a basic solution, and pH equal to 7 is neutral.
• ➕ Calculating pH of Strong Acids: Since strong acids completely dissociate, the concentration of $H^+$ is equal to the concentration of the acid. For example, for 0.1 M $HCl$, $[H^+]$ = 0.1 M.
• ➖ Calculating pH of Strong Bases: First, determine the concentration of $OH^-$. Then, calculate pOH using pOH = $-log[OH^-]$. Finally, use the relationship pH + pOH = 14 to find the pH.
• 🌡️ Neutralization Reactions: Reactions between acids and bases. A strong acid reacting with a strong base will produce water and a salt. The pH at the equivalence point will be 7.
• 💡 Important Formulas:
  • pH = $-log[H^+]$
  • pOH = $-log[OH^-]$
  • $[H^+][OH^-] = 1.0 \times 10^{-14}$
  • pH + pOH = 14

🧪 Practice Quiz

1. Which of the following is NOT a strong acid?
   1. $HCl$
   2. $HBr$
   3. $HF$
   4. $HNO_3$
2. What is the pH of a 0.01 M solution of $NaOH$?
   1. 2
   2. 12
   3. 7
   4. 1
3. Which of the following is a strong base?
   1. $NH_3$
   2. $CH_3COOH$
   3. $KOH$
   4. $H_2O$
4. What is the $[H^+]$ concentration in a solution with a pH of 3?
   1. $1 \times 10^{-3} M$
   2. $1 \times 10^{3} M$
   3. 3 M
   4. -3 M
5. What is the pOH of a solution with a pH of 4?
   1. 4
   2. 10
   3. 7
   4. 14
6. Which of the following statements is true regarding strong acids and bases?
   1. Strong acids and bases only partially dissociate in water.
   2. Strong acids completely dissociate, while strong bases partially dissociate.
   3. Strong bases completely dissociate, while strong acids partially dissociate.
   4. Strong acids and bases completely dissociate in water.
7. What is the pH of a 0.001 M solution of $H_2SO_4$?
   1. 1
   2. 2
   3. 3
   4. 11