Question #b54aa

1 Answer
May 2, 2017

Answer:

A Bronsted-Lowry base.

Explanation:

An Arrhenius base is a species than ionises in water to produce #OH^-# ions. Since #CaCO_3# contains no #OH^-# at all, it does not fulfil the definition of an Arrhenius base.

On the other hand, a Bronsted-Lowry base is a species that can accept a proton or #H^+# ion from a Bronsted-Lowry acid. The carbonate ion is able to take in protons to firstly form the bicarbonate ion and then form carbonic acid.

#CO_3 ^ (2-) + H^+ -> HCO_3 ^-#
# HCO_3 ^- + H^+ -> H_2 CO_3#

Carbonic acid is in equilibrium with #CO_2# and #H_2 O#.