Final answer:
The hydronium ion concentration of a solution at 25 °C with a pOH of 7.90 can be calculated to be approximately 7.94 × 10-7 M by using the relationship that pH + pOH = 14.
Step-by-step explanation:
The student is asking about the calculation of the hydronium ion concentration of a solution when given the pOH at 25 °C. Since the sum of the pH and pOH in any aqueous solution at 25 °C always equals 14, we can use this relationship to find the pH and subsequently the hydronium ion concentration.
With a pOH of 7.90, the pH is calculated by subtracting the pOH from 14, resulting in a pH of 6.10. The hydronium ion concentration can then be calculated using the pH by applying the formula concentration of hydronium ion = 10-pH. Plugging in the pH value.
We get a hydronium ion concentration of 10-6.10 M. Hence, the concentration of the hydronium ions in the solution would be approximately 7.94 × 10-7 M.