Sulfur compounds are often present in crude oil - VCE - SSCE Chemistry - Question 16 - 2002 - Paper 1

To determine which compound is produced in the smallest amount when burning crude oil containing 1% sulfur, we can analyze the chemical reactions involved in the combustion process.

1. Sulfur Combustion: When sulfur burns in the presence of oxygen, it primarily produces sulfur dioxide (SO₂) and sulfur trioxide (SO₃). Given that sulfur is present only at 1%, the resultant amounts of these compounds will be limited.

2. Water and Carbon Dioxide Production: The combustion of hydrocarbons in crude oil will primarily produce water (H₂O) and carbon dioxide (CO₂) in larger quantities compared to sulfur compounds. This is because the hydrocarbon content of the crude oil is significant, and hydrogen and carbon from these compounds are more abundant than sulfur.

3. Comparing Products: Since sulfur compounds are produced from a smaller fraction of the total fuel burned, and given that SO₃ forms from SO₂ under specific conditions, it can be inferred that:

   • SO₂ is a direct product of sulfur combustion and likely produced in a larger amount than SO₃.
   • Therefore, among the listed compounds, SO₃ would be produced in the smallest amount due to the limited sulfur content (1%) and the relative ratios in which these compounds are formed.

In conclusion, the compound produced in the smallest amount is A. SO₃.