If there is a leak from a valve on a sulfur dioxide tank, what color will the vapor fumes be when detected using ammonia?

When sulfur dioxide (SO2) leaks from a tank, the vapor fumes, when mixed with ammonia (often used in detection systems), will typically appear white. This white color manifests due to the formation of ammonium sulfate when sulfur dioxide reacts with ammonia. This reaction occurs as the sulfur dioxide combines with the water vapor present in the atmosphere and ammonia, creating a visible cloud of ammonium sulfate.

The distinct white cloud can serve as a significant visual indicator of the presence of sulfur dioxide, enabling operators to take appropriate cautionary measures. The other colors mentioned in the choices do not correlate with the chemical reactions and visual indicators associated with sulfur dioxide leaks detected by ammonia. Thus, the identification of the vapor fumes as white is crucial for safety protocols in handling and responding to sulfur dioxide leaks.