General Properties of Bases MCQs Quiz | Class 10

This quiz covers Class X Science (Code 086), Unit I: Chemical Substances – Nature and Behaviour, focusing on the General Properties of Bases. It includes questions on indicators and reaction behavior. Attempt the quiz to test your understanding, view your score, and download the answer sheet as a PDF.

Overview of Bases

Bases are chemical substances that have a bitter taste and feel soapy to the touch. Chemically, bases are substances that release hydroxide ions when dissolved in water. They turn red litmus paper blue. Bases that are soluble in water are specifically called Alkalis.

Key Properties and Reactions

  • Action on Indicators: Bases turn red litmus blue, phenolphthalein pink, and methyl orange yellow.
  • Reaction with Metals: Strong bases react with active metals like Zinc to produce a salt and Hydrogen gas. For example, Sodium Hydroxide reacts with Zinc to form Sodium Zincate and Hydrogen.
  • Neutralization: Bases react with acids to form salt and water. This reaction is called neutralization.
  • Reaction with Non-metal Oxides: Bases react with non-metal oxides (which are acidic in nature) to form salt and water, proving the basic nature of the hydroxide.

Summary Table: Indicator Changes

Indicator Color in Base
Red Litmus Blue
Phenolphthalein Pink
Methyl Orange Yellow
Turmeric Reddish Brown

Extra Practice Questions

  • 1. Which ion is responsible for the basic character of a substance? (Answer: Hydroxide ion)
  • 2. What is the pH range of a basic solution? (Answer: Above 7)
  • 3. Name the salt formed when NaOH reacts with Sulphuric Acid. (Answer: Sodium Sulphate)
  • 4. Why does dry baking soda not change the color of dry litmus paper? (Answer: Ions are only produced in the presence of water)
  • 5. What is the common name for Calcium Hydroxide? (Answer: Slaked Lime)