Final answer:
The gas that is dissolved on the right side of the heart in addition to O₂ is carbon dioxide (CO₂).
Step-by-step explanation:
The question is asking about the other gas that is dissolved on the right side of the heart, in addition to oxygen (O₂). Based on our knowledge of respiratory physiology, the gas that is primarily involved with O₂ in gas exchange within the circulatory system is carbon dioxide (CO₂). Carbon dioxide is produced as a waste product of cellular metabolism and is transported back to the lungs for exhalation. While O₂ and N₂ have similar solubility properties in the atmosphere, it is CO₂ that plays a central role in the respiratory system, not N₂. This is because CO₂ is produced by cells as they use oxygen to produce energy, and it must be removed from the body. CO₂ is dissolved in blood, both freely and as part of bicarbonate ions, and is also bound to hemoglobin to a lesser extent, a process separate from the binding of oxygen to hemoglobin.