Name two aqueous solutions that are often found at crime scenes
The correct answer and explanation is:
Two aqueous solutions often found at crime scenes are bloodstains (containing water, plasma, and cellular components) and bleach (sodium hypochlorite dissolved in water).
- Bloodstains: Blood is a common and significant substance found at many crime scenes. Blood is an aqueous solution because it is primarily composed of water (about 55-60%). In addition to water, blood contains plasma, red blood cells, white blood cells, and platelets, as well as dissolved substances such as proteins, glucose, and electrolytes. When blood is present at a crime scene, it is typically in the form of stains or spatter. Blood evidence can provide critical information about the nature of a crime, including the cause of injury, the sequence of events, and even the identity of the perpetrator in some cases. Blood analysis can also help to establish a timeline, determine the position of the victim, and identify relationships through DNA analysis.
- Bleach: Bleach, especially sodium hypochlorite (NaOCl) dissolved in water, is another aqueous solution often found at crime scenes. It is commonly used to clean and attempt to cover up traces of evidence, including bloodstains. Sodium hypochlorite is a powerful disinfectant and oxidizer that can break down biological materials and is often used to remove or alter the appearance of blood or other bodily fluids at crime scenes. It is also used for its ability to destroy DNA, which can make it harder for investigators to recover genetic evidence from a scene. The presence of bleach at a crime scene may indicate an attempt to destroy evidence, and forensic scientists can sometimes detect bleach residues even after attempts to clean a crime scene.
Both of these solutions are important in forensic investigations, as they help investigators understand the dynamics of a crime scene, the behavior of the suspect, and the interactions with various materials at the scene.