Final answer:
The pH of a solution prepared by dissolving 120.0 g NaOH in enough water to make 3.750 L of solution is approximately 13.488.
Step-by-step explanation:
To determine the pH of the solution, we need to first calculate the concentration of NaOH in the solution. We can use the formula: concentration (mol/L) = amount of solute (g) / molar mass (g/mol). The molar mass of NaOH is 22.99 g/mol for Na, 16.00 g/mol for O, and 1.01 g/mol for H, giving a total molar mass of 39.00 g/mol for NaOH.
Concentration (mol/L) = 120.0 g NaOH / 39.00 g/mol = 3.077 mol/L.
The pH of a solution can be determined using the formula: pH = -log[H+], where [H+] represents the concentration of hydrogen ions. In this case, since NaOH is a strong base, it completely dissociates in water to form hydroxide ions (OH-), so the concentration of hydroxide ions is equivalent to the concentration of NaOH.
pOH = -log[OH-] = -log(3.077) = 0.512
pH = 14 - pOH = 14 - 0.512 = 13.488.