Correct option is B
The correct answer is: (b) 0.0001
- pH is defined as: pH = -log[H⁺]
- Given, pH = 4 → [H⁺] = 10⁻⁴ mol/L
- Since HCl is a strong acid, it completely dissociates: HCl → H⁺ + Cl⁻
- Therefore, the molarity of the solution is equal to [H⁺] = 0.0001 mol/L
Information Booster:
• pH < 7 indicates an acidic solution; pH > 7 indicates a basic solution.
• Strong acids like HCl completely dissociate in water.
• For strong acids: Molarity = [H⁺] = 10^(-pH)
• pH scale ranges from 0 (strong acid) to 14 (strong base).
• A pH of 4 means the solution is weakly acidic.
• pH is a logarithmic scale; each unit change represents a tenfold change in [H⁺].
