What is the carbonate-ion, CO3-2, concentration in a 0.037 M carbonic acid solution?
a. 1.2 ´ 10-4
b. 4.2 ´ 10-7
c. 7.6 ´ 10-8
d. 4.8 ´ 10-11
e. 5.2 ´ 10-19
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To find the carbonate-ion (CO3-2) concentration in the given carbonic acid solution, you need to understand the dissociation of carbonic acid. Carbonic acid (H2CO3) dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-) in water. The bicarbonate ions (HCO3-) can further dissociate into hydrogen ions (H+) and carbonate ions (CO3-2). The balanced chemical equation for this dissociation can be represented as follows:
H2CO3 ⇌ H+ + HCO3-
HCO3- ⇌ H+ + CO3-2
We are given the concentration of carbonic acid, which is 0.037 M. Since the question asks for the concentration of carbonate ions (CO3-2), we must look at the second equilibrium reaction.
From the reaction, we can see that one mole of bicarbonate ion (HCO3-) produces one mole of carbonate ion (CO3-2). This means that the concentration of the carbonate ion (CO3-2) is equal to the concentration of bicarbonate ion (HCO3-).
Therefore, the carbonate-ion (CO3-2) concentration in the 0.037 M carbonic acid solution is also 0.037 M.
None of the given answer choices matches this value, so none of the provided options are correct.