When investigators search a fire scene what must the first focus be on?

When investigators search a fire scene what must the first focus be on?

The investigator should: Identify a distinct origin (location where the fire started) and an obvious fire cause (ignition source, first fuel ignited, and circumstances of the event that brought the two together).

What is the rapid combination of oxygen with fuel which produces a noticeable release of energy?

Combustion is rapid combination of oxygen with another substance, accompanied by production of noticeable heat and light. In an exothermic reaction, heat energy is liberated. In an endothermic reaction, heat energy is absorbed from the surroundings. Pyrolysis is the chemical breakdown of solid organic matter by heat.

When investigators search a fire scene what must they focus on first quizlet?

When investigators search a fore scene, the first focus must be on: Finding the origin of the fire.

What is the concentration at which a Vapour to fuel mixture in the air is capable of burning?

This means that gasoline can be ignited when it is in the air at levels between 1.4 and 7.6 percent. A concentration of gasoline vapour in air below 1.4 percent is too “lean” to burn. Gasoline vapour levels above 7.6 percent are too “rich” to burn.

Which is a chemical used to synthesize the explosive TATP?

Terrorists don’t need extensive chemistry training to prepare TATP. And the materials required to synthesize it—hydrogen peroxide, acetone, and mineral acid—are widely available in large quantities.

How do investigators determine the cause of a fire?

Fire investigators try to determine how fires begin by applying the scientific method. Through observation and measurement, they can formulate a hypothesis, test it and form a conclusion about the fire’s origin and cause.

When fire investigators look for evidence of an accelerant they may use?

T/F When fire investigators look for evidence of an accelerant, they may use dogs, samples of ash and debris and chemical sniffers.

Which are common chemical ingredients of black powder?

Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate (saltpeter).

Which pattern is caused by fires burning upward?

Section 4 of NFPA 921 states that any fuel source can cause inverse “V” patterns. When a fire burns against combustible wall, it creates an inverted “V” pattern. As the fire burns up and out it reaches the ceiling. Now the fire can no longer burn up, only out.

What is fire point of fuel?

The fire point of a fuel is the lowest temperature at which the vapour of that fuel will continue to burn for at least five seconds after ignition by an open flame of standard dimension.

What is flashpoint of fuel?

The flash point is the lowest temperature at which a volatile substance evaporates to form an ignitable mixture with air in the presence of an igneous source and continues burning after the trigger source is removed. From: Experimental Organic Chemistry, 2016.

What are the chemical processes in fire?

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

How do you identify a chemical reaction?

A chemical reaction takes place when new products are made from the reactants. Signs of a reaction could include bubbling, temperature change, color change, smoke, or change in odor. You may wish to demonstrate how to mix chemicals, apply heat, or add indicator.

What chemical reaction causes a gas to form?

Jump to navigation Jump to search. Forming gas is a mixture of hydrogen (mole fraction varies) and nitrogen. It is sometimes called a “dissociated ammonia atmosphere” due to the reaction which generates it: It can also be manufactured by thermal cracking of ammonia, in an ammonia cracker or forming gas generator.

How does chemical reaction help fire?

Heat is released when chemical bonds are broken and formed during chemical reactions. Since these reactions are ongoing, combustion releases more heat than is needed to sustain a fire. This is what makes a fire self-perpetuating, and also what makes it hot.