Chemistry
Bicarbonate is an ion with the chemical formula HCO3–. In the presence of water, it results in the following reactions:
(i) HCO3–(aq) + H2O(l) → H2CO3(aq) + OH–(aq)
(ii) HCO3–(aq) + H2O(l) → CO32–(aq) + H3O+(aq)
In the above reactions, the bicarbonate ion acts as _____.
a) a strong acid
b) a strong base
c) an acid in reaction (i) and as a base in reaction (ii)
d) a base in reaction (i) and as an acid in reaction (ii)
e) a weak base
c) an acid in reaction (i) and as a base in reaction (ii)
are you sure?
I apologize for the confusion. Upon further analysis, the correct answer is actually:
d) a base in reaction (i) and as an acid in reaction (ii)
To determine the role of the bicarbonate ion in the given reactions, we need to understand the behavior of different species in the reactions.
In reaction (i): HCO3–(aq) + H2O(l) → H2CO3(aq) + OH–(aq)
Based on this reaction, the bicarbonate ion (HCO3–) is reacting with water (H2O) to form carbonic acid (H2CO3) and hydroxide ion (OH–). This indicates that the bicarbonate ion is acting as a base by accepting a proton (H+) from water to form hydroxide ion (OH–).
In reaction (ii): HCO3–(aq) + H2O(l) → CO32–(aq) + H3O+(aq)
In this reaction, the bicarbonate ion (HCO3–) reacts with water (H2O) to form carbonate ion (CO32–) and hydronium ion (H3O+). Here, the bicarbonate ion acts as an acid by donating a proton (H+) to water, resulting in the formation of hydronium ion (H3O+).
From the above analysis, we can see that the bicarbonate ion acts as a base in reaction (i) and as an acid in reaction (ii). Therefore, the correct answer is option (c): an acid in reaction (i) and as a base in reaction (ii).