WARNING! This experiment is dangerous! You should NOT perform this at home. ONLY carry out this experiment, if you are a trained chemist, and you understand local safety and legal requirements, which are required to perform such experiments
- There are a few ways to obtain hydrogen sulfide in the laboratory. Let’s consider the most common two.
- The first of them is heating of sulfur/paraffin mixture. Place a piece of paraffin into the test- tube. Add some powdered sulfur. Clamp the test-tube on a stand. Fix it at an angle about 45o. Seal the test-tube with a stopper with a gas delivery tube. Heat the test tube gently. The released hydrogen sulfide could be detected by wet universal indicator paper. It turns red under action of hydrogen sulfide.
- The other way to synthesize hydrogen sulfide is the reaction between diluted hydrochloric (or sulfuric) acid and zinc or iron sulfide. Put some zinc sulfide to the flask. Fix up the thistle funnel and gas delivery tube at the flask mouth. Fill the thistle funnel with hydrochloric acid. Add some acid using the thistle funnel. Hydrogen sulfide is released.
- To test hydrogen sulfide gas properties prepare hydrogen sulfide water. Put the end of the gas delivery tube connected with a source of hydrogen sulfide to the beaker with cold water. Bubble the gas through the water for a while. Hydrogen sulfide is partially dissolved producing hydrogen sulfide water.
- Divide the obtained hydrogen sulfide water between two test tubes.
- Add a few drops of litmus indicator to the first test tube. The solution turns red.
- Add some copper sulfate solution to the second test tube. The formation of a black precipitate is observed.