Answer: CÓ2; alveoli
Explanation:
CÓ2 has a greater partial pressure in the pulmonary capillaries than in the alveoli, so it diffuses into the alveoli.
Despite the fact that CO2 has a smaller partial pressure difference, it should be noted that CÓ2 is much more soluble in blood than Ó2 which results in the CÓ2 that's exchanged between the blood and alveoli.
