Which of the following is known as Jones reagent?

CrO₃, H₂SO₄

The Jones Reagent is a solution of chromium trioxide in diluted sulfuric acid that can be used safely for oxidations of organic substrates in acetone. The reagent can also be prepared from sodium dichromate and potassium dichromate. Jones Reagent is especially suitable for the oxidation of secondary alcohols to ketones and of primary alcohols to carboxylic acids and in a few cases to aldehydes.