In the reaction $2H_2O \rightleftharpoons H_3O^{+} + OH^{-}$,water is

In the following reaction $HCO_3^{-} + H_2O \rightleftharpoons CO_3^{2-} + H_3O^{+}$,which two substances are Bronsted bases?

The conjugate base of the bicarbonate ion $(HCO_3^-)$ is:

In $NH_3$ and $PH_3$,the common property is

When a strong acid,strong base,or their salt are dissolved in water,they are completely ionised. If a strong acid is added to a strong base,$H^{+}$ ions from the former combine with $OH^{-}$ ions of the latter forming water. The formation of each water molecule liberates a certain quantity of energy and the reaction is exothermic. The heat liberated when one mole of water is formed by combining hydrochloric acid and sodium hydroxide is $13.7 \, kcal$. The heat liberated when one mole of water is formed by combining sulphuric acid and sodium hydroxide is......$kcal$

The conjugate base of $HCO_3^-$ is