Animated pictures of 37 chemical reaction principles and dangers---layered discoloration

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principle: The orange part below the test tube is potassium dichromate solution with some sulfuric acid added, and the transparent part above is diethyl ether, to which some hydrogen peroxide was added to initiate the reaction. Next, a violent reaction occurs in the system, and the organic layer above turns blue and produces gas. When hydrogen peroxide is added, the following reaction occurs in the aqueous phase: K2Cr2O7 + H2SO4 + H2O2 → 2 CrO5 + K2SO4 + 5H2O. The chromium peroxide (CrO5, also called chromium pentoxide) generated here is an unstable peroxide that can be dissolved in ether and brings a deep blue color. The unstable chromium peroxide will continue to react to form trivalent chromium salts.: 2CrO5 + 7H2O2 + 3H2SO4 → Cr2(SO4)3 + 10H2O + 7O2. The bubbles coming out of the test tube are the oxygen produced in this reaction. Highlights: Chromium peroxide is also blue in aqueous solution, but extraction with ether can keep the blue color for a longer period of time, making it easier to observe. Danger: Medium to high, the reaction is violent, so you need to wear gloves and goggles, and don't overfill the test tube.