What is the effect of dilution on the pH of a weak acid solution?
Practice Questions
1 question
Q1
What is the effect of dilution on the pH of a weak acid solution?
pH decreases
pH increases
pH remains constant
pH becomes neutral
Dilution of a weak acid decreases its concentration, which shifts the equilibrium to the right, increasing the concentration of H+ ions and thus increasing the pH.
Questions & Step-by-step Solutions
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Q
Q: What is the effect of dilution on the pH of a weak acid solution?
Solution: Dilution of a weak acid decreases its concentration, which shifts the equilibrium to the right, increasing the concentration of H+ ions and thus increasing the pH.
Steps: 7
Step 1: Understand what a weak acid is. A weak acid does not completely dissociate in water, meaning it does not release all of its H+ ions.
Step 2: Know what dilution means. Dilution is when you add more water to a solution, which decreases the concentration of the acid.
Step 3: Recognize that when you dilute a weak acid, you lower the concentration of the acid molecules in the solution.
Step 4: Remember that the equilibrium of a weak acid is a balance between the acid and its ions (H+ and its conjugate base).
Step 5: When you dilute the weak acid, the system tries to restore balance by shifting the equilibrium to the right, producing more H+ ions.
Step 6: As the concentration of H+ ions increases, the pH of the solution decreases (since pH is inversely related to H+ concentration).
Step 7: Conclude that dilution of a weak acid actually increases the pH, making the solution less acidic.
