An experiment was performed to model the formation of acid rain - HSC - SSCE Chemistry - Question 29 - 2060 - Paper 1

This experiment can be considered a suitable model for the formation of acid rain in a laboratory context.

The burning of sulfur produces sulfur dioxide (SO₂), which is a crucial component of acid rain. The combustion reaction can be represented as:

$S(s) + O_2(g) \rightarrow SO_2(g)$

In this setup, when water is introduced, it reacts with the sulfur dioxide, mimicking the interaction between rain and pollutants in the atmosphere, leading to the formation of sulfurous acid:

$H_2O(l) + SO_2(g) \rightarrow H_2SO_3(aq)$

The litmus paper turning red indicates the presence of acidic conditions, reinforcing that the experiment demonstrates the acidic nature of acid rain.

However, it should be noted that while the model captures essential chemical reactions, it lacks the scale and complexity of real environmental factors associated with acid rain formation. For example, it does not simulate other pollutants or natural sources of sulfur dioxide.