noun
precipitant; precipitating agent
Technical term in chemistry for a substance that causes precipitation from a solution.
この実験では沈殿剤として水酸化ナトリウムを使います。
In this experiment, we use sodium hydroxide as the precipitating agent.
沈殿 is the precipitation process or the precipitate itself, while 沈殿剤 specifically refers to the agent that causes precipitation.
Compound of 沈殿 (precipitation) + 剤 (agent, medicine).