Rio Tinto is a highly acidic river in southwestern Spain. This river has an average pH of 2.00. What are the [H₃O⁺] and the [OH⁻] of the river?

• A. [H₃O⁺] = 1.0×10⁻¹ M
  [OH⁻] = 1.0×10⁻¹³ M
• B. [H₃O⁺] = 1.0×10⁻² M
  [OH⁻] = 1.0×10⁻¹² M
• C. [H₃O⁺] = 2.0×10⁻² M
  [OH⁻] = 2.0×10⁻¹² M
• D. [H₃O⁺] = 2.0×10⁻² M
  [OH⁻] = 1.2×10⁻¹² M

Answer: (B)