Question

Choose the strongest acid from each group. a) \(\mathrm{HClO}, \mathrm{HBrO}, \mathrm{HIO}\) (b) \(\mathrm{HIO}, \mathrm{HIO}_{3}, \mathrm{HIO}_{4}\) c) \(\mathrm{HIO}, \mathrm{HBrO}_{2}, \mathrm{HBrO}_{4}\)

Short answer

Question: Identify the strongest acid from each group of compounds. a) HClO, HBrO, HIO b) HIO, HIO3, HIO4 c) HIO, HBrO2, HBrO4 Answer: The strongest acids from each group are: a) HIO b) HIO4 c) HBrO4

Step-by-step solution

Group a) Comparison

In this group, we need to compare the acidity strength of \(\mathrm{HClO}, \mathrm{HBrO}, \mathrm{HIO}\). As we move downward in a group, the acidity of the oxyacids tends to increase, because the atom bonded to the oxygen gets larger and has a lower electronegativity, which makes it easier for the hydrogen to dissociate. Thus, the strongest acid within this group is: \(\mathrm{HIO}\).

Group b) Comparison

In this group, we need to compare the acidity strength of \(\mathrm{HIO}, \mathrm{HIO}_{3}, \mathrm{HIO}_{4}\). The higher the oxidation state of the central atom and the more oxygen atoms it has, the stronger the acid will be. In this group, the iodine has the highest oxidation state and the maximum number of oxygen atoms in \(\mathrm{HIO}_{4}\). Therefore, the strongest acid within this group is: \(\mathrm{HIO}_{4}\).

Group c) Comparison

In this group, we need to compare the acidity strength of \(\mathrm{HIO}, \mathrm{HBrO}_{2}, \mathrm{HBrO}_{4}\). Here, we have two different halogens (iodine and bromine) with various oxygen atoms. We should first consider the difference in the oxidation state between \(\mathrm{HBrO}_{2}\) and \(\mathrm{HBrO}_{4}\). As discussed earlier, the compound with the higher oxidation state is more acidic. Thus, between these two compounds, \(\mathrm{HBrO}_{4}\) is the stronger acid. Now, we should compare \(\mathrm{HIO}\) and \(\mathrm{HBrO}_{4}\). In this case, iodine has a lower electronegativity than bromine and is located lower in the group; however, the higher oxidation state of bromine in \(\mathrm{HBrO}_{4}\) makes it the stronger acid. So, the strongest acid within this group is: \(\mathrm{HBrO}_{4}\). To summarize, the strongest acids from each group are: a) \(\mathrm{HIO}\) b) \(\mathrm{HIO}_{4}\) c) \(\mathrm{HBrO}_{4}\)