Question

Write the formula of an oxoanion of each of the following elements that cannot act as a reducing agent. (a) \(N\) (b) \(\underline{S}\) (c) \(\mathrm{Cl}\)

Short answer

Answer: The oxoanions that cannot act as reducing agents are (a) Nitrogen: \(\mathrm{NO_3^-}\), (b) Sulfur: \(\mathrm{SO_4^{2-}}\), and (c) Chlorine: \(\mathrm{ClO_4^-}\).

Step-by-step solution

Identify the highest oxidation state for nitrogen

The highest oxidation state for nitrogen in a stable oxoanion is +5. The reason is that, in higher oxidation states of nitrogen, it can act as a reducing agent by accepting electrons to move to a lower oxidation state.

Write the oxoanion formula for nitrogen

To write the formula of the oxoanion of nitrogen in a +5 oxidation state, we combine it with oxygen, which forms an ion with a 2- charge. Nitrogen forms an ion with a 5+ charge, so we need two oxygen atoms for each nitrogen atom to create a balanced ionic compound. Therefore, the oxoanion of nitrogen is \(\mathrm{NO_3^-}\).

Identify the highest oxidation state for sulfur

The highest oxidation state for sulfur in a stable oxoanion is +6. The reason is that, in higher oxidation states of sulfur, it can act as a reducing agent by accepting electrons to move to a lower oxidation state.

Write the oxoanion formula for sulfur

To write the formula of the oxoanion of sulfur in a +6 oxidation state, we combine it with oxygen, which forms an ion with a 2- charge. Sulfur forms an ion with a 6+ charge, so we need three oxygen atoms for each sulfur atom to create a balanced ionic compound. Therefore, the oxoanion of sulfur is \(\mathrm{SO_4^{2-}}\).

Identify the highest oxidation state for chlorine

The highest oxidation state for chlorine in a stable oxoanion is +7. The reason is that, in higher oxidation states of chlorine, it can act as a reducing agent by accepting electrons to move to a lower oxidation state.

Write the oxoanion formula for chlorine

To write the formula of the oxoanion of chlorine in a +7 oxidation state, we combine it with oxygen, which forms an ion with a 2- charge. Chlorine forms an ion with a 7+ charge, so we need four oxygen atoms for each chlorine atom to create a balanced ionic compound. Therefore, the oxoanion of chlorine is \(\mathrm{ClO_4^-}\). So, the oxoanions that cannot act as reducing agents are: (a) Nitrogen: \(\mathrm{NO_3^-}\) (b) Sulfur: \(\mathrm{SO_4^{2-}}\) (c) Chlorine: \(\mathrm{ClO_4^-}\)