Question

Assertion: $\text{C}{\text{O}}_2$ diffuses only from tissue to alveoli and not in the reverse direction.
Reason: $\text{C}{\text{O}}_2$ is 10 times more soluble than ${\text{O}}_2$.

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true but R is not a correct explanation of A
• C. A is true but R is false
• D. A and R are false

Answer 1

The correct option is C A is true but R is false

Concentration of $\text{C}{\text{O}}_2$ is more in the tissues than in the alveoli, thereby diffusion of $\text{C}{\text{O}}_2$ takes place from tissue to blood and from blood to alveoli and not in the reverse direction. The solubility of $\text{C}{\text{O}}_2$ is 20 times more than that of ${\text{O}}_2$ but the reason for the diffusion of $\text{C}{\text{O}}_2$ from tissue to alveoli is concentration gradient not the solubility of the gases.