What Are the Properties of Acids and Bases?
Acids and bases have distinct physical and chemical properties that help identify them. Acids taste sour and turn blue litmus red; bases taste bitter and turn red litmus blue. Both conduct electricity because they form ions in solution.
Key acid properties: sour taste, pH < 7, turn blue litmus red, react with metals and bases. Key base properties: bitter taste, slippery, pH > 7, turn red litmus blue, neutralize acids.
- •pH < 7
- •Sour taste
- •Turn blue litmus → red
- •Conduct electricity
- •React with bases
- •pH > 7
- •Bitter taste
- •Turn red litmus → blue
- •Conduct electricity
- •React with acids
Step-by-step worked examples
A substance turns blue litmus paper red. Is it an acid or base?
Litmus paper changes color: blue → red is a characteristic of acids. The substance is an acid.
A solution has pH 9 and feels slippery. Is it acidic or basic?
pH > 7 indicates a base. Slippery feeling is a property of bases. It is basic.
Vinegar (pH 2.4) and ammonia (pH 11) — identify each.
Vinegar: pH < 7 and sour taste → acid. Ammonia: pH > 7 and bitter smell → base.
Flashcards
Quick quiz
Q1.Which property is NOT true for acids?
Q2.A substance has pH 3. Is it…
Q3.What happens when acid and base mix?
Q4.Which indicator turns blue in bases?
The full card deck, worked steps and AI-tutor support for “What Are the Properties of Acids and Bases?” are in Notek — study by hand before your exam.
Common mistakes
Thinking only strong acids are 'real' acids. — Correct: Weak acids (vinegar, lemon juice) are still acids.
Confusing corrosive with acidic. — Correct: Many acids are weak and not corrosive; some bases (NaOH) are extremely corrosive.
Assuming pH tells you acid/base type. — Correct: pH tells strength, not type. All acids have pH < 7.
Forgetting that bases also conduct electricity. — Correct: Both acids and bases conduct because they form ions.
FAQ
What is the simplest way to identify an acid?
Acids turn blue litmus red and have pH < 7. (Never taste unknown substances!)
Are acidic drinks always harmful?
No — weak acids like vinegar and lemon juice are safe. Strong acids (hydrochloric) are very dangerous.
What is neutralization?
When an acid and base react, they form a salt and water: acid + base → salt + H₂O.
Why are bases slippery?
Bases break down oils and fats, creating a slippery film on skin.