In order to clean a clogged drain, 86g of sodium hydroxide is added to enough water to make 188mL of solution. What is the pH?
To find the pH of the solution, we need to calculate the concentration of hydroxide ions (OH-) in the solution using the amount of sodium hydroxide added.
Step 1: Convert grams of sodium hydroxide to moles.
Molar mass of NaOH = 22.99 g/mol + 16.00 g/mol + 1.01 g/mol = 39.99 g/mol
moles of NaOH = mass / molar mass = 86 g / 39.99 g/mol = 2.15 mol
Step 2: Calculate the concentration of OH- ions in the solution.
Volume of solution = 188 mL = 188 cm³ = 188 x 10⁻³ L
concentration of OH- ions = moles / volume of solution = 2.15 mol / 0.188 L = 11.44 M
Step 3: Calculate the pOH of the solution.
pOH = -log(OH- concentration) = -log(11.44) = 0.940
Step 4: Calculate the pH of the solution.
pH + pOH = 14
pH = 14 - 0.940 = 13.06
Therefore, the pH of the solution is 13.06.