The combination of lead vinegar and hydrogen sulfide
Lead vinegar is also a chemical agent. Hydrogen sulfide, a foul-smelling gas. When the two meet, a chemical change will occur.

The liquid of lead vinegar is static and clear. When hydrogen sulfide enters it, it is like a stone hitting water, and the waves change. In response, lead ions and sulfur ions combine, resulting in the sinking of lead sulfide. This dark color gradually gathers in the liquid, like a cloud falling on clear water.

Looking at the corresponding formula, lead vinegar ($Pb (CH_ {3} COO) _ {2} $) meets hydrogen sulfide ($H_ {2} S $) and converts into lead sulfide ($PbS $) and acetic acid ($CH_ {3} COOH $). The speed of response depends on various factors such as temperature and concentration. If the temperature is high and the concentration is high, it should be fast; if not, it will be slow.

Those who know the ancient art may know the wonder of this response. Use lead vinegar paper to test hydrogen sulfide, gas until the paper changes and the color turns black, and you will know the existence of hydrogen sulfide. This should be in the study of chemistry and work, both of which are essential, showing the wonder of material sympathies and the principle of endless changes.