1 A solution of sodium hydroxide NaOH was standardized again

1. A solution of sodium hydroxide (NaOH) was standardized against potassium hydrogen phthalate (KHP) A known mass of KHP was titrated with the NaOH solution until a light pink color appeared using phenolpthalein indicator. Using the volume of NaOH required to neutralize KHP and the number of moles of KHP titrated, the concentration of the NaOH solution was calculated. ut of Molecular formula of Potassium hydrogen phthalate: HKC8H404 Mass of KHP used for standardization (g) 0.5366 Volume of NaOH required to neutralize KHP (mL) 13.1606 Calculate the concentration of NaOH solution in (mol/L)

Solution

Mass of KHP used for standardization = 0.5366 g

Molar mass of KHP = 204.22 g/mol

Therefore, number of moles of KHP in 0.5366 g = 0.5366 g/ (204.22 g/mol) = 0.00262 moles

Therefore, number of moles of NaOH reacted with KHP = 0.00262

Concentration of NaOH = (0.00262 / 13.1606) x 1000 = 0.199 M