"On the Reaction of Hydrogen Sulfide and Lead Acetate"

The properties of the substances are different, and the chemical combination decomposes and changes are endless. Today, hydrogen sulfide ($H_2S $) and lead acetate (Lead Acetate), when they meet, there must be a wonderful change.

Hydrogen sulfide has the smell of rotting eggs, and its color is invisible and lively. Lead acetate is a salt, which often exists in medicines. When the gas of hydrogen sulfide encounters the liquid of lead acetate, there is a reaction.

The reaction image can be seen. The gas of hydrogen sulfide enters the lead acetate liquid, and in an instant, the liquid gradually forms a black precipitate. This black is lead sulfide ($PbS $). The combination of sulfur ions ($S ^ {2 -} $) in hydrogen sulfide and lead ions ($Pb ^ {2 + }$）， in lead acetate forms lead sulfide. The principle of its transformation follows the rules of chemistry, and anions and cations attract to form new products.

$H_2S + Pb (CH_3COO) _2\ longrightarrow PbS\ downarrow + 2CH_3COOH $

This reaction is also common in chemical experiments and can be used to test hydrogen sulfide. Because of the black precipitation of lead sulfide, the phenomenon is clear and easy to identify. And this reaction can reveal the subtlety of chemical changes and the wonder of the interaction between substances. The world's study of chemistry begins with such subtle reactions, and then explores the laws of change of all things for the benefit of the world.