How many electrons are removed from Cr2- when it is oxidized to CrO42-?

How many electrons are removed from Cr^2- when it is oxidized to CrO₄^2-?

Answer Details

When Cr^2- is oxidized to CrO₄^2-, it gains oxygen atoms and loses electrons. To determine how many electrons are lost, we need to look at the change in oxidation state of chromium in the reaction. In Cr^2-, the oxidation state of chromium is +2. In CrO₄^2-, the oxidation state of chromium is +6. Therefore, chromium has lost 4 electrons in the reaction (going from +2 to +6). So, the correct answer is 4 electrons.