Vinegar is a common household liquid used in cooking, cleaning, and food preservation. Understanding its chemical nature is important.
• Chemical Composition:
- Vinegar is typically 4–8% acetic acid (CH3COOH) dissolved in water.
- The remaining 92–96% is water along with trace amounts of flavoring compounds.
• Acidic Nature:
- Acetic acid gives vinegar its sour taste and characteristic pungent smell.
- The pH of vinegar ranges from 2.5 to 3.5, making it acidic.
- It turns blue litmus paper red, confirming its acidic property.
• Uses as an Acidic Re-agent:
- Cooking: Adds sour flavor to foods, used in pickling (preservation)
- Cleaning: Dissolves mineral deposits, grease, and some stains due to acidity
- Laboratory: Used as a mild acid in various experiments
- Traditional medicine: Sometimes used as a mild disinfectant
Why Other Options are Incorrect:
- (B) Alkaline re-agent: Incorrect. Alkaline substances have pH above 7 (e.g., baking soda, bleach). Vinegar is acidic, not alkaline.
- (C) Greasy solvent: While vinegar can help cut through grease to some extent, this is not its primary classification. “Greasy solvent” is not a standard chemical term, and vinegar is not primarily a solvent for grease (degreasers are usually alkaline).
- (D) Greasy absorbent: Incorrect. Vinegar does not absorb grease; it may help dissolve or remove it through chemical action, but “absorbent” is not an accurate description.
Final Answer: (A) Acidic re-agent