Question

In naming oxyanions, when there are more than two members in the series for a given element, what prefixes are used to indicate the oxyanions in the series with the fewest and the most oxygen atoms?

Short answer

When naming oxyanions with more than two members in the series, the prefix 'hypo-' is used for the oxyanion with the fewest oxygen atoms and the prefix 'per-' is used for the oxyanion with the most oxygen atoms. In addition, the suffix '-ite' is used for the oxyanion with fewer oxygen atoms, and the suffix '-ate' is used for the oxyanion with more oxygen atoms. For example, in the series of chlorine oxyanions, ClO⁻ is called hypochlorite, while ClO₄⁻ is called perchlorate.

Step-by-step solution

Identify the central atom and its oxidation state

The first step in naming oxyanions is identifying the central atom (usually a nonmetal) and its oxidation state. Different oxyanions of an element correspond to different oxidation states of the central atom.

Recognize the series' oxyanions

Once you have identified the central atom and its oxidation state, recognize all the oxyanions in the series.

Identify the oxyanions with the fewest and the most oxygen atoms

Among the series, find out the oxyanions with the fewest and the most oxygen atoms.

Assign the appropriate prefixes, as necessary

Oxyanions generally use these suffixes: "-ite" for the one with fewer oxygen atoms and "-ate" for the one with more oxygen atoms. When more than two oxyanions are in the series, we use prefixes to distinguish between them. The prefix 'hypo-' is used for the oxyanion with the fewest oxygen atoms, while the prefix 'per-' is used for the oxyanion with the most oxygen atoms. Let's summarize the prefixes and suffixes used to name oxyanions with the fewest and the most oxygen atoms for a given element when there are more than two members in the series: - Oxyanion with the fewest oxygen atoms: Prefix - 'hypo-' and Suffix - '-ite' - Oxyanion with the most oxygen atoms: Prefix - 'per-' and Suffix - '-ate' To give an example, consider the series of chlorine oxyanions: - ClO⁻ (hypochlorite) - Fewest oxygen atoms, so 'hypo-' + '-ite' is used - ClO₂⁻ (chlorite) - ClO₃⁻ (chlorate) - ClO₄⁻ (perchlorate) - Most oxygen atoms, so 'per-' + '-ate' is used