Question

(a) Give the chemical formulas and colors of the chromate and dichromate ions. (b) Which of these ions is more stable in acidic solution? (c) What type of reaction is involved in their interconversion in solution?

Short answer

(a) Chromate ion has the chemical formula \(CrO_4^{2-}\) and is yellow in color. Dichromate ion has the chemical formula \(Cr_2O_7^{2-}\) and is orange in color. (b) Dichromate ion is more stable in acidic solution. (c) The type of reaction involved in their interconversion is redox reaction.

Step-by-step solution

Identifying the chemical formulas and colors of chromate and dichromate ions

Chromate ion formula: \(CrO_4^{2-}\) Chromate ion color: Yellow Dichromate ion formula: \(Cr_2O_7^{2-}\) Dichromate ion color: Orange

Determining which ion is more stable in acidic solution

Dichromate ions are more stable in acidic solution. This is because, in acidic solution, the chromate ion would undergo a reduction process to form the more stable dichromate ion.

Identifying the type of reaction involved in the interconversion of chromate and dichromate ions in solution

The type of reaction involved in the interconversion of chromate and dichromate ions in solution is a redox reaction (reduction-oxidation reaction). This is because, during their interconversion, there is a transfer of electrons between the chromium atoms. In summary: (a) Chromate ion: \(CrO_4^{2-}\) (yellow), Dichromate ion: \(Cr_2O_7^{2-}\) (orange) (b) Dichromate ion is more stable in acidic solution. (c) The type of reaction involved in their interconversion is redox reaction.