要如何標定NaOH,舉列說明??

由於氫氧化鈉吸收空氣中的水和二氧化碳，故此不可能製成氫氧化鈉的基本標準溶液。換句話說，不可以憑秤取一定量氫氧化鈉溶於定量蒸餾水而製成氫氧化鈉的標準溶液。

通常是用稀酸的標準溶液以滴定方法來標定氫氧化鈉溶液。例如用移滴管把 Vb mL 的氫氧化鈉溶液（未標定、莫耳體積濃度為未知數 Mb）加進錐形瓶中，加入數滴甲基橙指示劑，以莫耳體積濃度 Ma 的鹽酸溶液滴定，直至溶液剛由黃色變成橙色。記錄所需鹽酸的體積 Va mL。

利用公式： Ma x (Va/1000) = Mb x (Vb/1000)
可計算得氫氧化鈉的莫耳體積濃度 Mb。

Potassium hydrogen phthalate, often called simply KHP. it is often used as a primary standard for acid-base titrations because it is solid and air-stable, making it easy to weigh accurately. It is not hygroscopic. It is also used as a primary standard for calibrating pH meters because, besides the properties just mentioned, its pH in solution is very stable. (from wikipedia)