The Process Of Combustion: How Much Do You Know? Trivia Quiz

Combustion is the correct answer because it refers to a chemical process where a volatile substance reacts rapidly with oxygen and releases heat. During combustion, the substance undergoes oxidation and burning, resulting in the transformation of the original substance into different products.

The correct answer is liquid because most airplane propulsion systems use liquid fuel. Liquid fuels, such as jet fuel or kerosene, are preferred for aircraft engines due to their high energy density and ease of handling. Liquid fuels can be easily stored and transported, making them suitable for long flights. Additionally, liquid fuels provide a more efficient combustion process, resulting in better performance and reduced emissions.

The given statement states that flammable and combustible liquids are liquids that can burn. It further explains that a liquid that ignites and burns easily at normal working temperatures is considered flammable. Therefore, the correct answer is "Flammable" as it accurately describes a liquid that can easily ignite and burn at normal temperatures.

During the combustion process, fuel reacts with an oxidizer to produce new chemical substances. These substances are released as exhaust gas. Exhaust gas is a byproduct of combustion and typically contains various gases such as carbon dioxide, carbon monoxide, nitrogen oxides, and water vapor. It is generated in engines, power plants, and other combustion processes.

The combustion process does not occur in the automobile fuel tank because there is no heat source. Combustion requires a heat source to initiate the reaction between gasoline and air, causing them to burn and release energy. Without a heat source, the gasoline and air mixture remains unburned and combustion does not take place.

Auto-ignition refers to the temperature at which a fuel can ignite spontaneously without any external ignition source. This means that the material can self-ignite without the need for a spark or flame. It is an important characteristic to consider when dealing with flammable substances, as it helps determine their safety and handling precautions.

In an airplane propulsion system, the oxidizer is usually in the form of a gas. This is because gases are easier to handle and transport compared to liquids or solids. They can be stored in tanks and easily fed into the combustion chamber for the chemical reaction that produces thrust. Liquids and solids would require more complex storage and delivery systems, making them less practical for airplane propulsion. LPG (liquefied petroleum gas) is a type of gas and could potentially be used as an oxidizer, but it is not commonly used in airplane propulsion systems.

Kerosene is the most common jet fuel because it has a high energy density and a low freezing point, making it suitable for use in high-altitude and cold temperature environments. It also has a relatively low flash point, which reduces the risk of accidental ignition. Kerosene is readily available and cost-effective, making it the preferred choice for powering jet engines.

Gasoline with a flashpoint of -40°C is considered as a flammable liquid because it has a low enough flashpoint to ignite easily when exposed to an ignition source, such as a spark or flame. Flammable liquids have a flashpoint below 37.8°C (-100°F) and can quickly vaporize, forming flammable vapors that can ignite and cause fires or explosions. Given that gasoline has a flashpoint well below this threshold, it is classified as a flammable liquid.

Avgas, short for aviation gasoline, is the correct answer because it is specifically designed for use in aircraft engines, including helicopters. It has a high octane rating to prevent engine knocking and provides the necessary power and performance required for flight operations. Diesel fuel is typically used in diesel engines, not helicopters. Octane is a measure of the fuel's resistance to knocking and is not a type of fuel itself. LPG, or liquefied petroleum gas, is commonly used as a fuel for heating and cooking, but not for helicopters.