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Fire Trivia Quiz Questions With Answers

Trivia quiz with answers about fire.

 

Fire Trivia Quiz Questions With Answers

What is fire?
A: Fire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products.

Slower oxidative processes like rusting or digestion are not included by what?
A: This definition.

Why is fire hot?
A: Because the conversion of the weak double bond in molecular oxygen, O2, to the stronger bonds in the combustion products carbon dioxide and water releases energy (418 kJ per 32 g of O2).

At a certain point in the combustion reaction, called the ignition point, what are produced?
A: Flames.

The flame is what portion of the fire?
A: The visible portion.

Flames consist primarily of what?
A: Carbon dioxide, water vapor, oxygen and nitrogen.

If hot enough, the gases may become what?
A: Ionized to produce plasma.

 
Fire in its most common form can result in conflagration, which has the potential to cause what?
A: Physical damage through burning.

Fire is an important process that affects what type of systems around the globe?
A: Ecological.

The positive effects of fire include what?
A: Stimulating growth and maintaining various ecological systems.

The negative effects of fire include what?
A: Hazard to life and property, atmospheric pollution, and water contamination.

If fire removes protective vegetation, heavy rainfall may lead to what?
A: An increase in soil erosion by water.

Also, when vegetation is burned, the nitrogen it contains is released into where?
A: The atmosphere, unlike elements such as potassium and phosphorus which remain in the ash and are quickly recycled into the soil.

This loss of nitrogen caused by a fire produces a long-term reduction in what?
A: The fertility of the soil, which only slowly recovers as nitrogen is "fixed" from the atmosphere by lightning and by leguminous plants such as clover.

 
How has fire been used by humans?
A: In rituals, in agriculture for clearing land, for cooking, generating heat and light, for signaling, propulsion purposes, smelting, forging, incineration of waste, cremation, and as a weapon or mode of destruction.

Fires start when a flammable or a combustible material, in combination with a sufficient quantity of an oxidizer such as oxygen gas or another oxygen-rich compound is exposed to what?
A: A source of heat or ambient temperature above the flash point for the fuel/oxidizer mix, and is able to sustain a rate of rapid oxidation that produces a chain reaction.

This is commonly called what?
A: The fire tetrahedron.

Fire cannot exist without all of these elements in place and what?
A: In the right proportions.

For example, a flammable liquid will start burning only if the fuel and oxygen are in the right what?
A: Proportions.

Some fuel-oxygen mixes may require a what?
A: A catalyst, a substance that is not consumed, when added, in any chemical reaction during combustion, but which enables the reactants to combust more readily.

If the oxidizer is oxygen from the surrounding air, the presence of a force of gravity, or of some similar force caused by acceleration, is necessary to produce what?
A: Convection, which removes combustion products and brings a supply of oxygen to the fire.

 
Without gravity, a fire rapidly surrounds itself with its own combustion products and non-oxidizing gases from the air, which exclude oxygen and do what?
A: Extinguish the fire.

Because of this, the risk of fire in a spacecraft is small when it is what?
A: Coasting in inertial flight.

This does not apply if oxygen is supplied to the fire by what?
A: Some process other than thermal convection.

Fire can be extinguished by removing what?
A: Any one of the elements of the fire tetrahedron.

How can a natural gas flame, such as from a stove-top burner be extinguished?
A: Turning off the gas supply, or covering the flame completely, which smothers the flame.

Fire is affected by what force?
A: The force of gravity.

A flame is a mixture of reacting gases and solids emitting what?
A: Visible, infrared, and sometimes ultraviolet light, the frequency spectrum of which depends on the chemical composition of the burning material and intermediate reaction products.

 
In many cases, such as the burning of organic matter, for example wood, or the incomplete combustion of gas, incandescent solid particles called soot produce what?
A: The familiar red-orange glow of "fire".

This light has a continuous what?
A: Spectrum.

Complete combustion of gas has what color?
A: A dim blue color due to the emission of single-wavelength radiation from various electron transitions in the excited molecules formed in the flame.

Usually oxygen is involved, but hydrogen burning in chlorine also produces what?
A: A flame, producing hydrogen chloride (HCl).

Other possible combinations producing flames, amongst many, are what?
A: Fluorine and hydrogen, and hydrazine and nitrogen tetroxide.

Hydrogen and hydrazine/UDMH flames are similarly pale blue, while burning boron and its compounds, evaluated in mid-20th century as a high energy fuel for jet and rocket engines, emits what?
A: Intense green flame, leading to its informal nickname of "Green Dragon".

Black-body radiation is emitted from what?
A: Soot, gas, and fuel particles, though the soot particles are too small to behave like perfect blackbodies.

 
There is also photon emission by what?
A: De-excited atoms and molecules in the gases.

Much of the radiation is emitted in what part of the spectrum?
A: The visible and infrared bands.

The color depends on temperature for the black-body radiation, and on what?
A: The chemical makeup for the emission spectra.

The dominant color in a flame changes with what?
A: Temperature.

The common distribution of a flame under normal gravity conditions depends on what?
A: Convection, as soot tends to rise to the top of a general flame, as in a candle in normal gravity conditions, making it yellow.

In micro gravity or zero gravity, such as an environment in outer space, convection no longer occurs, and the flame becomes what?
A: Spherical, with a tendency to become more blue and more efficient.

There are several possible explanations for this difference, of which the most likely is what?
A: That the temperature is sufficiently evenly distributed that soot is not formed and complete combustion occurs.

 
Experiments by NASA reveal that diffusion flames in micro gravity allow more soot to be completely oxidized after they are produced than what?
A: Diffusion flames on Earth, because of a series of mechanisms that behave differently in micro gravity when compared to normal gravity conditions.

In combustion engines, various steps are taken to eliminate what?
A: A flame.

The method depends mainly on what?
A: Whether the fuel is oil, wood, or a high-energy fuel such as jet fuel.

Objects whose surface is at a temperature above approximately 400 °C (752 °F) will glow, emitting what?
A: Light at a color that indicates the temperature of that surface.

The "adiabatic flame temperature" of a given fuel and oxidizer pair indicates what?
A: The temperature at which the gases achieve stable combustion.