Four common beverages are analyzed and found to have the following measured pH values…
CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Four common beverages are analyzed and found to have the following measured pH values at 25 °C.
• Black coffee: 5.0
• Soft drink: 3.0
• Sports drink: 4.0
• Distilled water: 7.0
Answer the following questions about their relative acid–base character.
(a) Identify which beverage is the most acidic and which is the least acidic.
(b) Describe, in words, how a one-unit change on the pH scale is related to a change in hydronium-ion concentration.
(c) A student claims that the soft drink (pH 3.0) is "twice as acidic" as the sports drink (pH 4.0). Evaluate this claim and explain your reasoning without performing explicit numerical calculations.
(d) Suppose the soft drink and the sports drink are mixed in equal volumes. Predict qualitatively (higher than 3.0, between 3.0 and 4.0, lower than 3.0, etc.) the resulting pH range of the mixture and justify your prediction.