Assertion: As per carbonic acid exchange theory of mineral salt absorption, `CO_(2)` released during respiration of roots forms 'H_(2)CO_(3) 'when dissolved in soil water Reason:`H_(2)CO_(3)` dissociates into `H^(+)` and `HCO_(3)` ions, where `H^(+)` ions exchange with anions adsorbed on clay particles.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. if both assertion and reason are true but reason is not the correct explanation of assertion
C. if assertion is true but reason is false
D. if both assertion and reason are false

Answer

C

Explanation

According to carbonic acid exchange theory, `CO_(2)` released during respiration of roots combines with soil water to produce carbonic acid `(H_(2)CO_(3))`. Carbonic acid dissociates into `H^(+)` and `HCO_(3)^(-)` ions in soil solution. These `H^(+)` ions may be exchanged for cations adsorbed on clay particles. the cations thsu released into soil solution from the clay particles, may be adsorbed on root cells in exchanges for `H^(+)` ions.