Question

Write the formula for each of the following chromium-containing ions, including the overall charge of the ion. a. chromous b. chromate c. chromic d. dichromate

Short answer

a. Chromous: \(\text{Cr}^{2+}\) b. Chromate: \(\text{CrO}_4^{2-}\) c. Chromic: \(\text{Cr}^{3+}\) d. Dichromate: \(\text{Cr}_2\text{O}_7^{2-}\)

Step-by-step solution

a. Chromous

Chromous indicates that chromium is in its +2 oxidation state. Thus, the ion is represented as \(\text{Cr}^{2+}\).

b. Chromate

Chromate is a polyatomic ion containing chromium in its +6 oxidation state. The chromate ion has the formula \(\text{CrO}_4^{2-}\). The overall charge of the chromate ion is -2.

c. Chromic

Chromic indicates that chromium is in its +3 oxidation state. Therefore, the ion is represented as \(\text{Cr}^{3+}\).

d. Dichromate

Dichromate is a polyatomic ion containing two chromium atoms in their +6 oxidation state. The dichromate ion has the formula \(\text{Cr}_2\text{O}_7^{2-}\). The overall charge of the dichromate ion is -2. In summary, the formulas and overall charges for the given chromium-containing ions are: a. Chromous: \(\text{Cr}^{2+}\) b. Chromate: \(\text{CrO}_4^{2-}\) c. Chromic: \(\text{Cr}^{3+}\) d. Dichromate: \(\text{Cr}_2\text{O}_7^{2-}\)