Final answer:
Three broad categories of fuel gases include natural gas, propane, and butane, which is represented by option number 1. Propane and methane are key examples, widely used as fuels for their efficient combustion and significant heat energy release.
Step-by-step explanation:
Three broad categories of fuel gases include natural gas, propane, and butane. These gases are classified due to their common use as fuel sources with high energy content and are particularly relevant in the context of combustion reactions. Propane is widely used as a heat source for engines and homes, whereas natural gas, which is mainly composed of methane (CH4), holds a significant role in the world's energy consumption, providing approximately 20% of world energy needs and 25% of United States needs. Natural gas is also a potent greenhouse gas and its composition varies between biogenic and thermogenic origins.
It's worth noting that propane and other hydrocarbons are commonly used as fuel because their combustion produces a significant amount of heat energy, which makes them very efficient. For instance, the balanced equation for the combustion of propane is C3H8 (l) + 5O2 (g) → 3CO2 (g) + 4H2O (l). Similarly, the combustion of methane can be represented by the equation CH4 + 2O2 → CO2 + 2H2O + heat.