Final answer:
An acceptable alternative for the proper shipping name 'Petroleum gases, liquefied' are liquefied petroleum gas (LPG) and liquefied natural gas (LNG), which are used for economical transportation and as cleaner alternative fuels.
Step-by-step explanation:
The proper shipping name 'Petroleum gases, liquefied' can also be referred to as liquefied petroleum gas (LPG) or liquefied natural gas (LNG). LNG is primarily made up of methane that has been cooled to below about -162°C. LPG, though similar, has a composition that typically includes propane, butane, and other light hydrocarbons that are also found in a liquefied state due to pressurization or cooling.
Liquefied natural gas is an alternative fuel that can be used to power vehicles and reduce greenhouse gases, as it burns more cleanly than gasoline or diesel. Their compact, liquefied state allows for more economical and easier transportation compared to their gaseous forms. When discussing these substances, remember that gasoline is a liquid derived from petroleum and consists of medium-sized hydrocarbon chains, while natural gas is mostly methane in gaseous form unless it is cooled to become LNG.