When solid sodium carbonate dissolves, the carbonate ion reacts with water according to the equilibrium below.
CO32−+H2O⇌HCO3−+OH−
Which statement most accurately describes water's role in this equilibrium?
a) Water accepts a proton, so it functions as a Brønsted–Lowry base.
b) Water is amphoteric in general and in this reaction both donates and accepts a proton.
c) Water donates a proton, so it functions as a Brønsted–Lowry acid.
d) Water is not acting as an acid or base because its concentration remains essentially constant and therefore is not involved in the equilibrium.