Find the pH of a 0.001M NaOH (Sodium hydroxide) Solution

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To find the pH of a 0.001 M solution of sodium hydroxide (NaOH), you can follow these steps:

Understand that pH is a measure of the acidity or alkalinity of a solution. It is defined as the negative logarithm (base 10) of the concentration of hydrogen ions (H+) in the solution.
pOH = -log[H+]

But because we're dealing with a base, NaOH we need first to use the equation:
pOH = -log[OH-]

Identify the dissociation: Sodium hydroxide (NaOH) is a strong base that completely dissociates in water to release hydroxide ions (OH-) and sodium ions (Na+). The balanced equation for this dissociation is:
NaOH → Na+ + OH-

Determine the concentration of hydroxide ions: Since NaOH is a strong base, the concentration of hydroxide ions in the solution will be the same as the initial concentration of the base. In this case, it is 0.001 M.

Calculate the pOH: To find the pOH, take the negative logarithm (base 10) of the hydroxide ion concentration. Mathematically, pOH is calculated using the formula:
pOH = -log[OH-]

Substituting the concentration of hydroxide ions into the formula:
pOH = -log[0.001]

Using a scientific calculator or logarithm tables, evaluate -log(0.01) to find the pOH value.

pOH = -log(1) = 3

Calculate the pH: To calculate the pH, use the relationship between pH and pOH. The sum of pH and pOH is always equal to 14 at 25 degrees Celsius:
pH + pOH = 14

Therefore, the pH can be determined by subtracting the pOH from 14:
pH = 14 - 3 = 11

Therefore, the pH of a 0.001 M solution of NaOH is 11, indicating a highly alkaline (basic) solution.

Note: Keep in mind that the pH scale ranges from 0 to 14, where pH 7 is considered neutral, pH values below 7 indicate acidity, and pH values above 7 indicate alkalinity.