Iron and Luminol

The video tutorial demonstrates how blood can be detected at a crime scene using a chemical reaction involving luminol, hydrogen peroxide, and sodium hydroxide. Fake blood is created using potassium ferrous cyanide, which acts as a substitute for real blood. The experiment shows how the iron in the fake blood catalyzes the breakdown of hydrogen peroxide, leading to a chemiluminescence reaction that emits a blue flash. This reaction is sensitive enough to detect even tiny traces of iron, making it a valuable tool in forensic science. However, the test does not conclusively prove the presence of blood.

What is the purpose of using potassium ferrous cyanide in the demonstration?

• To neutralize the luminol

• To increase the temperature of the reaction

• To change the color of the solution

• To act as a real blood substitute

What visual effect indicates the presence of blood during the experiment?

• A yellow shimmer

• A green spark

• A blue flash

• A red glow

Which component in the fake blood acts as a catalyst in the reaction?

• Luminol

• Sodium hydroxide

• Hydrogen peroxide

• Potassium ferrous cyanide

What is the role of iron in the chemiluminescence reaction?

• It provides the blue color

• It is consumed in the reaction

• It acts as a catalyst

• It reacts with sodium hydroxide

What is the chemical symbol for iron, which plays a crucial role in the reaction?

• In

• Ir

• Fe

• I

Why is the luminol test considered very sensitive?

• Because it works only in complete darkness

• Because it changes color rapidly

• Because it can detect even tiny traces of iron

• Because it requires a large amount of iron

What is the main limitation of the luminol test in forensic science?

• It only works on fresh blood

• It requires a large sample size

• It does not conclusively prove the presence of blood

• It is too expensive