Which compound is identified by lead acetate paper for detection?

Lead acetate paper is specifically used for the detection of hydrogen sulfide (H2S). When hydrogen sulfide comes into contact with lead acetate, it reacts to form lead sulfide, which is a dark-colored compound. This color change—often resulting in a darkening of the lead acetate paper—serves as an indicator of the presence of hydrogen sulfide in the environment.

The specificity of lead acetate paper for hydrogen sulfide is due to its selective chemical reaction. Other compounds listed do not produce a similar reaction with lead acetate. For instance, sulfur dioxide can be detected using other methods but does not interact with lead acetate in the same way. Ammonia and methane also do not produce any color change on lead acetate paper and therefore are not detected by this method. Understanding these interactions is critical in environmental compliance and the accurate monitoring of gases in air quality assessments.