Question 1: Define oxygen evolution in the context of Earth's atmosphere.

Answer: Oxygen evolution refers to the process by which oxygen is produced and released into the atmosphere, primarily through photosynthesis in plants and algae.

Question 2: Explain the role of photosynthesis in oxygen evolution.

Answer: Photosynthesis uses sunlight to convert carbon dioxide and water into glucose and oxygen, releasing oxygen into the atmosphere as a byproduct.

Question 3: What is the chemical equation for photosynthesis involving oxygen?

Answer: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂

Question 1: If a plant performs photosynthesis producing 12 moles of oxygen per hour, how many molecules of oxygen is this? (Use Avogadro's number: 6.022 x 10²³ molecules per mole.)

Answer: 7.23 x 10^24 molecules

Question 2: A pond has an algae population that produces 2.5 grams of oxygen per day. Calculate the number of moles of oxygen produced daily. (Molecular weight of O₂ = 32 g/mol.)

Answer: 0.078 moles

Question 1: Describe a simple experiment to demonstrate oxygen evolution in a laboratory setting, including the variables you would control.

Answer: An experiment can involve using a aquatic plant like Elodea submerged in water inside a test tube with a small amount of sodium bicarbonate. When exposed to light, oxygen bubbles form and can be collected over water. Variables to control include light intensity, temperature, and water quality.

Question 2: List three safety precautions to consider when conducting experiments related to oxygen evolution.

Answer: Ensure proper ventilation, avoid open flames near oxygen-generating setups, and handle chemicals like sodium bicarbonate with care.

Question 1: A certain aquatic plant produces oxygen at a rate of 0.5 grams per hour. If this rate continues, how many grams of oxygen will it produce in 24 hours? Show your calculation.

Answer: 12 grams

Question 2: If an industrial process produces 1000 liters of oxygen daily at standard temperature and pressure, how many moles of oxygen is this? (Use 22.4 L/mol for ideal gas at STP.)

Answer: 44.64 moles

Question 1: Explain how understanding oxygen evolution is important for developing renewable energy sources, such as artificial photosynthesis.

Answer: Understanding oxygen evolution helps scientists design systems that mimic natural photosynthesis to produce clean energy. Artificial photosynthesis can generate oxygen and fuels like hydrogen, reducing reliance on fossil fuels and combating climate change.

Question 2: Identify two industries that utilize knowledge of oxygen evolution and describe their applications.

Answer: The medical industry uses oxygen produced through electrolysis for respiratory therapy, and the steel industry uses oxygen in blast furnaces to assist in metal smelting.