Which of the following statements regarding the mechanism and applications of vinegar is incorrect?
Show answer & explanation
Correct answer: D
Explanation
Solution: The correct answer is The cleaning effectiveness of vinegar increases when mixed with baking soda due to the formation of a strong alkaline solution that breaks down grease and proteins.
Explanation:
☛ Vinegar is an acidic solution containing acetic acid (CH₃COOH), while baking soda is a basic compound called sodium bicarbonate (NaHCO₃).
☛ When mixed together, an acid-base neutralization reaction takes place, producing water, carbon dioxide (CO₂) gas, and sodium acetate.
☛ This reaction neutralizes the acidic properties of vinegar and the alkaline properties of baking soda, effectively reducing their individual cleaning powers rather than creating a strong alkaline solution.
☛ Although the initial foaming (release of CO₂ bubbles) can physically help loosen grime, the resulting liquid is essentially neutral salt water.
Extra Exam-Relevant Facts:
☛ Preservative Action: Vinegar lowers the pH to around 2.5–3.0, inhibiting the growth of pathogenic and food spoilage bacteria.
☛ Biological Synthesis: Industrial production involves a two-step process: anaerobic fermentation of sugars to ethanol by yeast, followed by aerobic conversion of ethanol to acetic acid by Acetobacter bacteria.
☛ Limescale Removal: Acetic acid decomposes hard-water scale (calcium carbonate, CaCO₃) into soluble calcium acetate, water, and carbon dioxide.
Important One-Liners for Upcoming Exams:
☛ What is the chemical formula of acetic acid? → CH₃COOH (or C₂H₄O₂)
☛ What is the typical concentration of acetic acid in commercial household vinegar? → 4% to 8% by volume
☛ What is pure, water-free acetic acid commonly called? → Glacial acetic acid
☛ What gas is evolved when vinegar reacts with baking soda? → Carbon dioxide (CO₂)
☛ What is the IUPAC name of acetic acid? → Ethanoic acid