Problem 61 - Chemistry: The Central Science

Question

Give the chemical formula for (a) chlorite ion, (b) chloride ion, (c) chlorate ion, (d) perchlorate ion, (e) hypochlorite ion.

Step-by-Step Solution

Answer

(a) ClO₂⁻, (b) Cl⁻, (c) ClO₃⁻, (d) ClO₄⁻, (e) ClO⁻

Step 1: (a) Chlorite Ion

To write the chemical formula for the chlorite ion, first recognize that it is an oxyanion of chlorine. The suffix "-ite" tells us that it has a lower oxidation state than the "-ate" ion. In this case, the chlorite ion has a -1 charge while the chlorate has a -1 charge as well. The oxidation number of chlorine in the chlorite ion is +3. The chemical formula of the chlorite ion is: ClO₂⁻.

Step 2: (b) Chloride Ion

The chloride ion is simply a chlorine atom that has gained one electron to achieve a stable electron configuration. As a result, it carries a -1 charge. The chemical formula for the chloride ion is: Cl⁻.

Step 3: (c) Chlorate Ion

The chlorate ion is an oxyanion of chlorine with the ending "-ate," indicating a higher oxidation state than the chlorite ion. The oxidation number of chlorine in the chlorate ion is +5. The chemical formula for the chlorate ion is: ClO₃⁻.

Step 4: (d) Perchlorate Ion

The perchlorate ion is also an oxyanion of chlorine, but the prefix "per-" indicates it has the highest oxidation state among oxyanions of the same element. The oxidation number of chlorine in the perchlorate ion is +7. The chemical formula for the perchlorate ion is: ClO₄⁻.

Step 5: (e) Hypochlorite Ion

The hypochlorite ion is another oxyanion of chlorine. The prefix "hypo-" indicates it has the lowest oxidation state among oxyanions of the same element. The oxidation number of chlorine in the hypochlorite ion is +1. The chemical formula for the hypochlorite ion is: ClO⁻.