How do you determine the maximum amount of propane to dispense into a container?

The correct approach to determining the maximum amount of propane to dispense into a container involves understanding the relationship between the container's water capacity and the appropriate fill percentage for propane. Propane liquid occupies a certain volume and expands when converted to gas; thus, knowing the maximum volume of propane that can be safely stored in a container is crucial.

The accepted standard is to multiply the water capacity of the container by 42%. This percentage accounts for the expansion properties of propane and ensures that the container is not overfilled, which could lead to safety hazards due to pressure changes in varying temperatures. When propane is stored, this percentage allows for the necessary vapor space — the area above the liquid propane in the tank which provides room for gas expansion.

The other choices propose different percentages, which do not align with the established safety guidelines for propane storage. The percentages suggested in those options would not provide adequate space for gas expansion, thereby heightening the risk of overpressure within the container and potential safety issues.