Determination of the exact concentration of the standard solution By carbon dioxide absorption from the air occurs in the sodium hydroxide solution of sodium bicarbonate, which changes the pH of the titrant. To prevent this, a drying tube filled with soda lime is placed on the reagent bottle. The exact concentration of the sodium hydroxide solution is determined using the standard potassium hydrogen phthalate. The potassium hydrogen phthalate is dried in the oven before the titer determination for 2 hours at 120°C and cooled in a desiccator. ChemTron Titroline 6000自動(dòng)電位滴定儀 優(yōu)萊博 TitroLine 7500KF容量法卡式水份滴定儀 優(yōu)萊博 TitroLine 6000自動(dòng)電位滴定儀