Technical Standards and Safety Authority (TSSA) G3 Practice Exam

What would the likely cause be if orange flashes were evident in a gas flame?

1. Dust burning in the flame

2. Carbon dioxide burning in the flame

3. Hydrogen burning in the flame

4. Nitrogen burning in the flame

The correct answer is: Dust burning in the flame

The presence of orange flashes in a gas flame typically indicates incomplete combustion, which often results from impurities in the gas or foreign materials within the combustion zone. When dust or other particulate matter enters the flame, it can ignite and produce a flickering orange or yellow light, as well as a change in the overall color of the flame. This is often seen as a sign that the combustion process isn't occurring efficiently, leading to the release of energy in ways that create the characteristic color change. In contrast, the other options describe gases that typically do not produce an orange flash when burned. Pure carbon dioxide, hydrogen, and nitrogen do not produce the same visible effects in a flame. For example, hydrogen typically burns with a blue flame, indicating a complete combustion, while nitrogen is generally inert in combustion and would not normally yield visible flames at typical combustion temperatures. Thus, the presence of dust as the likely cause for orange flashes is indicative of incomplete burning due to contamination, making it the most appropriate answer.