The discovery of the entombed cat at the end of the story is an example of .

Situational Irony

Explanation:

The narrator does not expect to find another black cat, especially what happened to the first one.

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

there's the proffessional site that will you.