Le Châtelier's principle applies to gas exchange reactions in human lungs. Carbon dioxide gas combines with water in the blood to form carbonic acid:
H2O + CO2 = H2CO3
During exercise, the concentration of CO2 in the blood increases. How would
this affect the reaction's equilibrium?
A. It would favor the forward reaction.
B. It would favor the backward reaction.
C. It would maintain the reaction's equilibrium.
D. More information is needed to assess the reaction's equilibrium.

The correct option is;

A. It would favor the forward reaction

Explanation:

Le C_h_a_t_e_l_i_e_r_'s principle states that for a system in dynamic equilibrium a change in the volume, pressure, concentration, or temperature will cause a predictable shift in the reaction to bring about a shift in the equilibrium position which counteracts the change and bring about the establishment of a new equilibrium

Therefore, in the reaction, H₂O + CO₂ → H₂CO₃, we have;

An increase in the amount of the CO₂ concentration in the blood, increases the quantity of the reactants more than the quantity present at equilibrium, therefore, the number of reaction between the H₂O and the CO₂ increases resulting in the formation of more H₂CO₃, therefore, favoring the forward reaction.