Identify the correct statement from among the following.

• Bases are substances that release hydroxide ions (OH⁻) in aqueous solutions and have the following properties:

  • They turn phenolphthalein pink, a key characteristic test for bases.
  • They are bitter in taste, not sour.
  • Bases have a pH value greater than 7, indicating their alkalinity.
  • Bases turn red litmus blue, not blue litmus red.

• Option A: Incorrect, as bases are bitter, not sour. Sourness is a characteristic of acids.

• Option C: Incorrect, as bases have a pH value greater than 7.

• Option D: Incorrect, as bases turn red litmus blue, not blue litmus red.

Key Facts:
● Common bases: Sodium hydroxide (NaOH), potassium hydroxide (KOH), and calcium hydroxide [Ca(OH)₂].
● Phenolphthalein indicator: Colourless in acids but turns pink in basic solutions.
● Uses of bases: Bases are widely used in soaps, detergents, and neutralization reactions.
● pH scale: Bases typically range between 7.1 and 14.
● Industrial significance: Bases are critical in chemical industries for processes like saponification and manufacturing cleaning agents.