Question

Coal gas: (a) Is not a good fuel (b) Is not used for lighting purpose (c) Burns with non-smoky flame (d) Burns with a smoky flame

Short answer

Option C: Burns with a non-smoky flame.

Step-by-step solution

Understanding Coal Gas Properties

Coal gas is produced from the gasification of coal. It is known to be a useful gaseous fuel. Understanding this foundational property helps us evaluate the given options.

Analyzing Option A

Option A suggests that coal gas is not a good fuel. This is incorrect because coal gas is traditionally used as a fuel due to its combustibility.

Evaluating Option B

Option B states that coal gas is not used for lighting purposes. This is false since historically, coal gas has been used in gas lamps for lighting.

Considering Option C

Option C claims that coal gas burns with a non-smoky flame. This is generally true as coal gas burns cleanly due to its composition of hydrogen, methane, and other light hydrocarbons.

Reviewing Option D

Option D asserts that coal gas burns with a smoky flame. This is incorrect since the presence of light hydrocarbons leads to a cleaner, non-smoky flame.

Selecting the Correct Answer

Based on the analysis, Option C is the most accurate. Coal gas does indeed burn with a non-smoky flame, fitting its use as a cleaner fuel source.

Key concepts

Gaseous Fuel

Coal gas is an important example of a gaseous fuel. Gaseous fuels are energy sources that are in a gas state at room temperature. Typical examples include natural gas and propane, but coal gas is distinguished due to its historical significance.

• Being in a gaseous state means these fuels are more easily mixed with air, enhancing their combustibility and efficiency.
• Unlike solid fuels like wood or coal, gaseous fuels burn more cleanly and clean-burning properties make them preferable in many applications.

Coal gas, specifically, is a type of manufactured gas derived from heating coal, which is why it contains various hydrocarbons. The advantages of gaseous fuels include ease of transport, cleaner burning, and efficient energy conversion, making them highly favored compared to their solid counterparts.

Gasification Process

The gasification process is a crucial method in producing coal gas. It involves heating coal in the absence of air or with a controlled amount of air. This process helps break down coal into a gas mixture primarily made up of hydrogen, methane, carbon monoxide, and a few other gases.

• Gasification is a thermochemical process, converting carbonaceous materials into carbon monoxide, hydrogen, and carbon dioxide.
• The end products are more versatile in use, especially in energy production, chemical industries, and fuel generation.

This process not only produces a clean-burning fuel but also allows the separation of impurities found in coal, which supports the clean energy movement. In recent times, it is valued for its environmental benefits compared to direct coal burning.

Non-smoky Flame

When coal gas is burned, it typically produces a non-smoky flame. This quality makes it attractive for use in various applications where clean combustion is desired.

• A non-smoky flame is achieved because coal gas is largely composed of simple hydrocarbons and hydrogen, both of which combust cleanly.
• Emissions are minimized, making coal gas a more environmentally friendly option than solid fuels.

Historically, this property allowed coal gas to be used widely in domestic heating and lighting before the widespread adoption of electricity. Even today, fuels that produce non-smoky flames are crucial for maintaining air quality and reducing pollution.

Historical Uses of Coal Gas

Coal gas played a significant role in history, particularly during the 19th and early 20th centuries. It was one of the first widely used manufactured fuels that offered a cleaner and more consistent burn compared to traditional wood or coal.

• Historically, coal gas was essential for street lighting in cities before electricity became commonplace, offering a reliable source of light through gas lamps.
• It also found use in homes for heating and lighting, providing a significant improvement over open fire methods.

These uses not only improved everyday life but helped spark the development of urban infrastructure focused on gas distribution. Despite being largely replaced by electricity now, coal gas's influence on energy distribution systems remains a topic of study and admiration for many historians and energy experts.