Chrome alum or chromium alum is a safe salt that produces dark, purplish crystals. Key Takeaways An alum is a type of chemical compound with the general formula XAl(SO4)2·12H2O, where X is a monovalent cation such as potassium or ammonium Alum crystals form octahedral shapes in their purest form Mixed Chrome Alum crystals consist of potassium alum (KAl(SO4)2·12H2O) mixed with chrome alum (KCr(SO4)2·12H2O)… Continue reading Chrome Alum Crystal
Even though the aspirin produced by this method is reasonably pure, it should never be used as a medication. Key Takeaways Aspirin or ASA (acetylsalicylic acid) can be synthesized by turning the hydroxyl group of salicylic acid into an ester group (R-OH → R-OCOCH3) In the body, however, aspirin is again metabolized to salicylic acid,… Continue reading Aspirin Synthesis
Hydrogen peroxide is a strange substance. It is somewhat similar to water but has completely different properties. For example, you should never try to put out a fire with hydrogen peroxide. Hydrogen peroxide can react as a powerful oxidizer in high concentrations. Unlike water, H2O2 is extremely reactive and breaks down easily. In the process,… Continue reading Reactivity of hydrogen peroxide
The peroxo acids, also called peracids for short, and their salts are of great importance for the chemical industry. They all carry the group -O-O-H or -O-O-. The perborates and percarboxylic acids are known as bleaching agents in detergents. Sulfur also forms peroxy acids: peroxomonosulfuric acid H2SO5 (Caro’s acid) and peroxydisulfuric acid H2S2O8. They have… Continue reading Peroxo Compounds
Peroxycarbonates (also known as peroxocarbonates) play an important role in the synthesis of plastics, for example in the production of PVC or PE. Many heavy-duty detergents contain percarbonates as bleaching substances. Peroxy(di)carbonates contain bound peroxides The underlying peroxycarboxylic acid H2CO4 is not stable and rather hypothetical, but there are the anions HCO4– and CO42-, which… Continue reading Percarbonate Compounds
When it comes to the structure of hydrogen peroxide, many think of its chemical brother H2O. But you should also keep an eye out for O2 because H2O2 lies chemically right in the middle. Here are some rough structures that come up: The structures drawn in red are more or less correct. So, as so… Continue reading The structure of the H2O2 molecules
You have certainly performed the electrolysis of sodium chloride solutions before. Why don’t you investigate the electrolysis behavior of aqueous ammonium chloride solutions? Once again you can learn a lot of chemistry. Electrolysis of ammonium chloride solution Fill an ammonium chloride solution (w = 10%) into a U-tube with a diaphragm. Dip two clean graphite… Continue reading Electrolysis of ammonium chloride solution
Chemicals Copper (II) sulfate solution (c=0.1 mol l) (Xn), ammonia solution (c=2 mol/l) (Xi), concentrated sulfuric acid (C) How-to a) Add ammonia solution drop by drop to the copper (II) sulfate solution in a test tube until a light blue precipitate forms. Then add more ammonia solution until a clear solution forms. b) Now add… Continue reading Copper tetramine complex
Equipment 2 beakers (100 ml), 2 watch glasses, spatula, dropper pipettes, Bunsen burner to cover the beaker. Chemicals Ammonia water (C), ammonium chloride (Xi), sodium hydroxide (C), red litmus paper, or universal indicator paper. How-to Put on protective goggles. Do not smell the gases directly! 1 Analysis of liquid ammonia solution A few ml of… Continue reading Testing for nitrogen
Equipment 2-L round bottomed flask, 2-L beaker, 2-hole stopper, Glass tube (2 ft. in length), Ring stand and clamps, medicine dropper, Chemicals Dry NH3 gas or apparatus to produce NH3, Water, Phenolphthalein How-to Fill the 2-L flask with ammonia gas and seal it with a rubber stopper. Ammonia can be generated by gently heating a… Continue reading Ammonia fountain
Equipment Beaker (100 ml) or test tube. Chemicals Conc. Ammonia water (C), conc. Hydrochloric acid (C). How-to Put on protective goggles. Keep both substances away from the body. For better contrast, it is recommended to use a dark (black) background. When ready, open both bottles and hold them close to each other. We can also… Continue reading Ammonium chloride mist
Everyone should know, that it is not wise to extinguish every fire with water. Special hazards need special care. We can demonstrate this with an interesting pyrotechnic mixture: Negative X. This is a metal-catalyzed, strongly exothermic redox reaction which is initiated by nascent hydrogen (formed from ammonium ions of the acidic hydrolyzing salts and the… Continue reading Water sensitive flash powder
