Lactic acid sodium hydroxide solution

Lactic acid sodium hydroxide solution (1mol / L)
Preparation: Take clarified saturated solution of sodium hydroxide 56mL, add boiling over cold water to make into 1000mL.
Calibration: in 105 ℃ drying to constant weight basis of potassium hydrogen phthalate about 6g, accurately weighed,Add boiling over cold water 50mL, shake, to try to dissolve; add 2 drops of phenolphthalein indicator solution, with the Droplets, ferrous lactate, should make potassium hydrogen phthalate is completely dissolved, the solution was titrated to Pink.Ethyl lactate of sodium hydroxide (1mol / L) is equivalent to 204.2mg phthalate Potassium. According to the liquid consumption of potassium hydrogen phthalate and dosage, calculate the concentration of the solution.
Storage: polyethylene plastic bottle, sealed and stored; plug two holes, each hole insert the glass Branch, a soda lime tube and connected to a suction of the fluid for use.