Final answer:
The pH of the 2.35 x 10⁻⁴ M HCl solution is 3.63, and the pOH is 10.37. These values are calculated using the negative logarithm of the HCl concentration for pH, and subtract from 14 to find the pOH, maintaining two significant figures.
Step-by-step explanation:
The student's question involves finding the pH and pOH of a solution with a given concentration of HCl. Since HCl is a strong acid, it ionizes completely in solution. The concentration of HCl given is 2.35 x 10⁻⁴ M, which also represents the concentration of hydrogen ions (H⁰⁺⁴) because HCl ionizes completely.
To find the pH, we take the negative logarithm (base 10) of the hydrogen ion concentration:
pH = -log [H⁰⁺⁴] = -log [2.35 x 10⁻⁴]
After calculating the negative logarithm, we get:
pH = 3.63 (rounded to two decimal places as the concentration of HCl has two significant figures)
Now to find the pOH:
The pOH of a solution can be calculated by subtracting the pH from 14, because pH + pOH = 14 at 25°C.
pOH = 14.00 - pH = 14.00 - 3.63 = 10.37
Therefore, the pOH of the solution is 10.37, and we can see that the resulting pH is acidic based on the pH scale where values lower than 7 indicate acidity.