Question

Why is the Jones reagent (H2CrO4) an enviornmental and health hazard; please and thank you.

Answer 1

As we know that, every action has reaction (Newton's Law)

Jones reagent is excellent oxidizing agent and converts alcohols to carboxylic acids via carbonyl compounds with few exceptions in high yield within short span of time.

At the same time there are some environmental and health issues. Since Chromium (VI) compounds are carcinogenic in nature, hence during the reaction the fumes of Cr (VI) will enter in atmosphere. If we inhale that air, causes some types of cancers.

In the view of this it's use slowly reduced even though it has wonderful synthetic applications.