Question 1: Explain in your own words what is meant by the term 'concentration' in a chemical solution.

Answer: Concentration refers to the amount of a substance (solute) present in a given volume or mass of solvent or solution, usually expressed in units like mol/dm³ or g/dm³.

Question 2: Why is measuring the concentration of a substance important in forensic investigations?

Answer: Measuring concentration helps identify and compare substances found at crime scenes, such as blood, drugs, or toxins, aiding in evidence analysis and solving cases.

Question 3: Fill in the blank: The formula to calculate concentration in mol/dm³ is ________.

Answer: Concentration = moles of solute / volume of solution (dm³)

Question 1: A forensic scientist extracts 0.05 mol of a toxin from a blood sample and dissolves it in 0.5 dm³ of solution. Calculate the concentration of the toxin in mol/dm³.

Answer: 0.1 mol/dm³

Question 2: If the concentration of a drug in a blood sample is 0.2 g/dm³ and the molar mass of the drug is 250 g/mol, what is the molar concentration?

Answer: 0.0008 mol/dm³

Question 1: Describe a basic procedure that a forensic scientist might use to determine the concentration of a substance in a sample, including key safety precautions.

Answer: A forensic scientist would first prepare a sample by dissolving it in an appropriate solvent, then use a calibrated instrument such as a spectrophotometer to measure absorbance. The concentration is determined by comparing the absorbance to a standard curve. Safety precautions include wearing gloves, safety goggles, working in a fume hood, and handling chemicals with care to avoid contamination or exposure.

Question 1: A blood sample from a crime scene shows a drug concentration of 0.15 g/dm³. The forensic lab finds that the standard solution of the drug has a concentration of 0.5 g/dm³ and a known molar mass of 300 g/mol. How does the sample's molar concentration compare to the standard?

Answer: The blood sample's molar concentration is 0.0005 mol/dm³, which is lower than the standard solution's concentration of 1.67 mol/dm³.

Question 1: Explain how the concept of concentration helps forensic scientists determine the severity or amount of substances like drugs or toxins present in a crime scene sample.

Answer: Concentration indicates the amount of substance present, helping to estimate dosage, toxicity, or the quantity of evidence, thereby assisting in establishing the nature of the crime or victim.

Question 2: Discuss how advancements in concentration measurement techniques could improve forensic investigations in the future.

Answer: Advancements such as more sensitive sensors and portable devices could allow for rapid, accurate, on-site analysis of samples, reducing analysis time and increasing reliability, thereby strengthening evidence and aiding quicker justice.