Final answer:
The even balance of H+ and OH- ions results in a neutral solution with a pH of 7. The sum of pH and pOH is always 14, and pH is defined as the negative logarithm of the hydronium ion concentration.
Step-by-step explanation:
The pH system is designed such that an even balance of H+ and OH- ions in a solution produces a neutral solution with a pH of 7. According to the pH scale, neutral solutions have pH = 7, acidic solutions have pH < 7, and basic solutions have pH > 7. The relationship between pH and pOH is captured by the formula 14 = pH + pOH, indicating that the sum of pH and pOH in any aqueous solution always adds up to 14. If a solution is neutral, then the pH and the pOH both are 7, because that is the point where their sum equals 14.
Additionally, the definition of pH as the negative logarithm of the hydronium ion concentration [H3O+] allows for easy conversion between pH and [H3O+]. It is important to note that while pH values are typically between 0 and 14, the pH scale itself has no limits. When the hydronium ion concentration of a solution is 1.0 × 10-7 M, which is the case for pure water, the pH is exactly 7.00.