A chemist dissolves of pure sodium hydroxide in enough water to make up of solution. Calculate the pH of the solution. (The temperature of the solution is .) Be sure your answer has the correct number of significant digits.

A chemist dissolves 707.mg of pure sodium hydroxide in enough water to make up 100.mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25°C.) Be sure your answer has the correct number of significant digits.

Step 1: Calculate the molarity of NaOH

M = mass of solute / molar mass of solute × liters of solution

M = 0.707 g / 40.0 g/mol × 0.100 L

M = 0.177 M

Step 2: Write the basic dissociation reaction

NaOH → Na⁺ + OH⁻

The molar ratio of NaOH to OH⁻ is 1:1, Then, [OH⁻] = 0.177 M.

Step 3: Calculate the pOH

pOH = -log [OH⁻]

pOH = -log 0.177

pOH = 0.752

Step 4: Calculate the pH

pH + pOH = 14.00

pH = 14 - pOH = 14.00 - 0.752

pH = 13.25