Final answer:
The acidity of iodic acid compared to chloric acid can be explained by the strength of their O-H bonds and the stability of their conjugate bases. Iodic acid's weaker O-H bond and less stable conjugate base make it a weaker acid than chloric acid.
Step-by-step explanation:
The acidity of a molecule is determined by several factors, including the strength of its O-H bond and the stability of its conjugate base.
In the case of iodic acid (HIO3) and chloric acid (HClO3), the difference in acidity can be explained by examining their chemical bonding.
The O-H bond in iodic acid is weaker than the O-H bond in chloric acid, making it easier for iodic acid to release an H+ ion and dissociate as an acid. This is because the size of the iodine atom is larger than the chlorine atom, resulting in a longer and weaker bond.
As a result, iodic acid is a weaker acid compared to chloric acid.
Additionally, the stability of the conjugate base is another factor that affects acid strength. The conjugate base of iodic acid (iodate ion, IO3-) is less stable than the conjugate base of chloric acid (chlorate ion, ClO3-). This is due to the larger size of the iodate ion, which makes it more difficult to stabilize the negative charge.
Therefore, the conjugate base of iodic acid is less stable and less likely to accept a proton, making iodic acid a weaker acid.