Final answer:
The pH of 9.18 corresponds to a basic solution, and we can calculate the hydronium ion concentration as 10^-9.18 and the hydroxide ion concentration found by first determining pOH as 14 - pH and then calculating 10^-pOH.
Step-by-step explanation:
The pH of a solution is a measure of its acidity or basicity.
The given pH of 9.18 indicates a basic solution since it is greater than 7.
To calculate the concentration of hydronium ions (H3O+), we use the formula: pH = -log[H3O+].
Therefore, [H3O+] = 10^-pH = 10^-9.18,
which we can calculate using the 10% key for the inverse logarithm on a calculator.
Next, to find the pOH of the solution, we use the relationship that pH + pOH = 14 at 25°C.
Subtracting the given pH from 14 gives us the pOH: pOH = 14 - 9.18 = 4.82.
From this, we can determine the concentration of hydroxide ions (OH-) using
pOH = -log[OH-], so [OH-]
= 10^-pOH
= 10^-4.82.
The resulting concentrations are expressed as Molarity (M), and they describe the acidity or basicity of a solution at a certain temperature, reflecting the presence of hydronium and hydroxide ions.