Q1. What is the Ksp of AgCl if the solubility of AgCl in water is 1.33 x 10^-5 M? (2023)
Solution:
Ksp = [Ag+][Cl-] = (1.33 x 10^-5)(1.33 x 10^-5) = 1.78 x 10^-10.
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Q2. What is the pH of a 0.1 M solution of ammonium chloride (NH4Cl)? (2019) 2019
Solution:
NH4Cl is a salt of a weak base and strong acid, pH < 7. Calculate using hydrolysis: pH ≈ 4.75.
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Q3. What is the concentration of H+ ions in a solution with pH 3? (2019) 2019
Solution:
Concentration of H+ = 10^(-pH) = 10^(-3) = 0.001 M.
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Q4. What is the pH of a 0.001 M solution of hydrochloric acid?
Solution:
pH = -log(0.001) = 3.
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Q5. What is the pH of a 0.05 M acetic acid solution (Ka = 1.8 x 10^-5)? (2023)
Solution:
Using the formula for weak acids, pH = 0.5(pKa - log[C]) where pKa = -log(1.8 x 10^-5) ≈ 4.74. pH = 0.5(4.74 - log(0.05)) ≈ 4.7.
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Q6. In a buffer solution, which of the following components is essential? (2023)
Solution:
A buffer solution is made from a weak acid and its conjugate base (salt), which helps maintain pH.
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Q7. What is the pH of a 0.001 M acetic acid solution (Ka = 1.8 x 10^-5)?
Solution:
Using the formula for weak acids, pH = 0.5(pKa - logC) = 0.5(4.74 - log(0.001)) = 3.87.
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Q8. If 0.1 M acetic acid (CH3COOH) is 1% ionized, what is the concentration of H+ ions?
Solution:
Ionization = 1% of 0.1 M = 0.001 M, so [H+] = 0.001 M.
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Q9. What is the pH of a 0.1 M solution of sodium acetate (Ka for acetic acid = 1.8 x 10^-5)?
Solution:
Using the formula for salt of weak acid, pH = 14 + 0.5(pKa + logC) = 14 + 0.5(4.74 + log(0.1)) = 9.25.
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Q10. In a buffer solution, which component resists changes in pH? (2020)
Solution:
A buffer solution typically consists of a weak acid and its conjugate base (salt), which helps to resist changes in pH when small amounts of acid or base are added.
