Answer: 0.0001M
Step-by-step explanation:
Given that:
[H₃O⁺] (hydronium concentration) = ?
pH of aqueous solution = 4.00
pH is the negative logarithm of hydrogen ion [H+] or hydroxonium ion [H₃O⁺] in a solution. Mathematically it is expressed as:
pH = -log[H₃O⁺]
4.00 = -log[H₃O⁺]
[H₃O⁺] = Antilog (-4.00)
[H₃O⁺] = 0.0001M
Thus, 0.0001M is the [H₃O⁺] (hydronium concentration) of an aqueous solution that has a pH of 4.00