Sodium hydroxide, which you might know as lye, is a key ingredient in many skin care and beauty products. Here's what it does and why it's safe.

Dilute sodium hydroxide solution is used in tests for some metal ions close ion Electrically charged particle, formed when an atom or molecule gains or loses electrons., ...

Add sodium hydroxide solution slowly drop wise. Note your observations in the table. Continue adding sodium hydroxide drop wise to any precipitates until a large excess is present (about 2/3 full).