Acids & Bases — Set 4
Chemistry · अम्ल और क्षार · Questions 31–40 of 60
Which gas is released when sodium bicarbonate reacts with acetic acid?
Correct Answer: B. Carbon dioxide
• **Carbon dioxide** = The reaction between baking soda and vinegar releases carbon dioxide gas as effervescence. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: Oxygen; C: Carbon monoxide; D: Hydrogen
What is the pH value of pure water at room temperature?
Correct Answer: D. 7
• **7** = Pure water is neutral and has a pH of exactly 7 at 25°C. • **7** — Pure water is neutral and has a pH of exactly 7 at 25°C • 💡 Wrong-option analysis: A: 1; B: 14; C: 0
Which of the following is a property of bases?
Correct Answer: A. Turns red litmus blue
• **Turns red litmus blue** = Bases have a bitter taste and turn red litmus paper blue. • (Contextual detail from explanation) • 💡 Wrong-option analysis: B: Reacts with metals to form O2; C: Sour taste; D: pH less than 7
Which acid is used as a preservative in food items like pickles?
Correct Answer: A. Acetic acid
• **Acetic acid** = Acetic acid in the form of vinegar is used to preserve pickles by inhibiting bacterial growth. • (Contextual detail from explanation) • 💡 Wrong-option analysis: B: Sulfuric acid; C: Nitric acid; D: Hydrochloric acid
Which substance is used to treat a wasp sting, which is basic in nature?
Correct Answer: C. Vinegar
• **Vinegar** = Since a wasp sting is alkaline, a mild acid like vinegar is used to neutralize it. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: Soap; B: Caustic soda; D: Baking soda
What is the nature of non-metal oxides generally?
Correct Answer: B. Acidic
• **Acidic** = Non-metal oxides like carbon dioxide and sulfur dioxide are acidic in nature. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: Amphoteric; C: Neutral; D: Basic
Which base is commonly used in window cleaning solutions?
Correct Answer: B. Ammonium hydroxide
• **Ammonium hydroxide** = Ammonium hydroxide is effective at removing grease and stains without leaving streaks on glass. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: Sodium hydroxide; C: Magnesium hydroxide; D: Calcium hydroxide
Which of the following is an example of an amphoteric oxide?
Correct Answer: D. Aluminum oxide
• **Aluminum oxide** = Aluminum oxide is amphoteric because it can react with both acids and bases. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: Carbon dioxide; B: Sodium oxide; C: Magnesium oxide
What is the chemical formula for Nitric Acid?
Correct Answer: C. HNO3
• **HNO3** = HNO3 is the chemical formula for nitric acid, a highly corrosive mineral acid. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: CH3COOH; B: H2SO4; D: HCl
Which indicator stays colorless in acidic solutions and turns pink in basic ones?
Correct Answer: D. Phenolphthalein
• **Phenolphthalein** = Phenolphthalein is a synthetic chemical indicator that is colorless below pH 8. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: Methyl orange; B: Turmeric; C: Litmus