Neco Model Questions Vol1 2024 Biology Question 4

A group of students investigated the rate of respiration in germinating beans using a closed‑system respirometer. The set‑up consisted of a sealed 250 mL bottle containing 10 germinating beans immersed in 50 mL of water. The bottle was connected to a graduated tube filled with water; as the beans respired, O₂ was consumed and the water level in the tube fell, indicating the volume of gas taken up. Two experiments were performed: • At 25 °C the water level fell 12 mL in 5 minutes. • At 35 °C the water level fell 18 mL in 5 minutes. Assume that the volume of water displaced is equal to the volume of O₂ consumed, and that the gas behaves ideally at the experimental temperature and pressure. Use 22.4 L as the molar volume of an ideal gas at STP (0 °C, 1 atm) and the molar mass of CO₂ = 44 g mol⁻¹. Answer the following: