Q43 P - Chemistry: Molecular Nature Of Matter And Change

Question

When solid CrO₃ is dissolved in water, the solution is orange rather than the yellow of H₂CrO₄ - How does this observation indicate that CrO₃ is an acidic oxide?

Step-by-Step Solution

Answer

When CrO₃ dissolved in water forms an orange solution, it means that there are dichromate ions present in solution. Dichromate is formed from chromate ions in acidic medium. Therefore, presence of orange solution indicates an acidic environment with dissolved chromate (VI) oxide.

Step 1: Definition of Coordination Compound

A coordination complex consists of a central atom or ion, which is typically metallic and is named the coordination centre, and a surrounding array of bound molecules or ions, that are successively called ligands or complexing agents.

Step 2: Solve the given statements

When CrO₃ dissolved in water forms an orange solution, it means that there are dichromate ions present in solution. Dichromate is formed from chromate ions in acidic medium. Chromate ions come from chromic acid that is formed when chromate (VI) oxide gets dissolved in water. Therefore, presence of orange solution indicates an acidic environment with dissolved chromate (VI) oxide.