Question

Iodic acid has the molecular formula \(\mathrm{HIO}_{3}\). Write the formulas for the following: (a) the iodate anion, (b) the periodate anion, (c) the hypoiodite anion, (d) hypoiodous acid, (e) periodic acid.

Short answer

The formulas for the given ions and acids are: (a) \(IO_3^-\), (b) \(IO_4^-\), (c) \(IO^-\), (d) \(HIO\), and (e) \(HIO_4\).

Step-by-step solution

(a) Iodate anion

To find the iodate anion, we need to identify the central atom, which is iodine (I), and its corresponding polyatomic ion. The polyatomic ion for iodate is IO₃⁻. Therefore, the iodate anion has the formula \(IO_3^-\).

(b) Periodate anion

The periodate anion is a polyatomic ion that involves iodine (I) and oxygen (O). The periodate anion has one more oxygen atom than the iodate anion, so we add one oxygen atom to the existing \(IO_3^-\) formula. Therefore, the formula for the periodate anion is \(IO_4^-\).

(c) Hypoiodite anion

The hypoiodite anion is another polyatomic ion that involves iodine (I) and oxygen (O). The hypoiodite anion has two fewer oxygen atoms than the iodate anion. So, we subtract two oxygen atoms from the existing \(IO_3^-\) formula. Therefore, the formula for the hypoiodite anion is \(IO^-\).

(d) Hypoiodous acid

To find the formula for hypoiodous acid, we need to combine the hypoiodite anion (\(IO^-\)) with a hydrogen atom (H). When we do this, we remove the negative charge on the iodine ion and create a molecule of hypoiodous acid. The formula for hypoiodous acid is \(HIO\).

(e) Periodic acid

To find the formula for periodic acid, we need to combine the periodate anion (\(IO_4^-\)) with a hydrogen atom (H). Doing this removes the negative charge on the iodine ion and creates a molecule of periodic acid. The formula for periodic acid is \(HIO_4\).