Question 1: Define carbon dioxide and describe its role in the human respiratory system.

Answer: Carbon dioxide is a colorless gas produced during respiration when cells break down glucose; it is expelled from the body through the lungs to maintain pH balance.

Question 2: Explain the chemical mechanism by which carbon dioxide reacts with limewater to produce a precipitate.

Answer: Carbon dioxide reacts with calcium hydroxide in limewater to form calcium carbonate, a white precipitate, through a chemical reaction where CO₂ combines with Ca(OH)₂.

Question 3: What is the significance of testing for carbon dioxide in medical diagnostics?

Answer: Testing for carbon dioxide helps assess a patient's respiratory function, monitor ventilation efficiency, and detect respiratory or metabolic disorders.

Question 1: Calculate the volume of carbon dioxide produced if a patient’s body produces 0.5 moles of CO₂ during respiration. (Use the ideal gas law, where 1 mole of gas occupies 22.4 liters at standard temperature and pressure).

Answer: 11.2 liters

Question 2: A sample of exhaled air contains 4% carbon dioxide by volume. If a patient exhales 500 mL of air, how many milliliters of CO₂ are present?

Answer: 20 mL

Question 1: Describe the steps involved in testing for carbon dioxide using limewater in a medical laboratory setting.

Answer: Collect a sample of the gas, bubble it through limewater, and observe for a white precipitate of calcium carbonate, indicating the presence of CO₂.

Question 2: Identify at least two safety precautions that must be taken when handling carbon dioxide in a laboratory.

Answer: Ensure proper ventilation to prevent gas buildup and wear safety goggles to protect eyes from accidental splashes or reactions.

Question 1: A patient’s exhaled air tests positive for carbon dioxide when bubbled through limewater. If the limewater turns cloudy within 30 seconds, what does this indicate about the patient’s respiratory health?

Answer: It indicates normal or adequate respiratory function, as the presence of CO₂ suggests proper gas exchange in the lungs.

Question 2: During a medical test, a sample of exhaled air contains 5% CO₂. If the total exhaled volume is 600 mL, estimate the volume of CO₂ in the sample.

Answer: 30 mL

Question 1: Explain how capnography, a medical technology that measures carbon dioxide levels in exhaled air, is used to monitor a patient's respiratory status during surgery.

Answer: Capnography provides real-time monitoring of CO₂ levels in exhaled air, allowing medical professionals to assess ventilation effectiveness, detect respiratory depression, and ensure proper anesthesia depth during surgery.

Question 2: Discuss the importance of accurate carbon dioxide testing in neonatal intensive care units (NICUs).

Answer: Accurate CO₂ testing in NICUs is crucial for monitoring the respiratory health of newborns, especially those on ventilators or with respiratory issues, to prevent complications such as hypoventilation or hyperventilation, and to maintain proper blood pH levels.