The Home Laboratory

                  Reaction of potassium ferrocyanide with zinc chloride Potassium hexacyanoferrate (II) is a lemon yellow coloured inorganic complex, also called potassium ferrocyanide. The ferrocyanide ion consists of iron in the +2 state coordinately bonded to six cyano ligands. It is a versatile chemical, and is widely used in qualitative chemical analyses. However, it should not be confused with potassium ferricyanide, which consists of iron in the +3 state coordinately bonded to six cyano ligands, and has reddish crystals. For this experiment, four solutions were prepared in test tubes. The first was of copper nitrate, the second was of zinc chloride, and the third was of ferrous chloride. The fourth solution was of potassium ferrocyanide in distilled water. The potassium ferrocyanide solution was added to all the other three test tubes, with visible results. The three test tubes contain the products of the reaction with potassium ferroc...

                    The structure of glycerol. Picture courtesy Google. You may have heard of glycerin, or glycerol, which is an essential component in many cosmetics and soap cakes. It is used as a laxative, a moisturizer, and an antibacterial drug. This experiment, depicting the oxidation of glycerol by potassium permanganate, is extremely dangerous, and should not be attempted by inexperienced personnel. The IUPAC name for glycerol is propane-1,2,3-triol. Glycerol is a polyhydric alcohol, where three hydroxyl groups are attached to adjacent atoms in a propane chain. Due to this, it is highly viscous, and miscible in water. It has a sweet taste. Potassium permanganate is an extremely powerful oxidizing agent, which in an acidic medium, normally converts 1° alcohols to carboxylic acids, and 2° alcohols to ketones (they can be oxidized further to carboxylic acids under drastic conditions). However, in the case of glycerol, a spectacular ...

A beaker containing sugar solution. Redox reactions can be spectacular, especially when accompanied by a mélange of colour changes. This reaction depicts the reduction of the manganese ion in potassium permanganate (+7 state) to manganese dioxide (+4 state). Potassium permanganate is an extremely versatile chemical, and a very strong oxidizing agent. It was once widely used to disinfect water. The colour of the compound stems from the coloured permanganate ion. However, when reduced in an alkaline medium, various colours are observed, owing to the intermediate compounds formed. This array of chromatic changes earned this reaction the name 'Chemical Chameleon'. REAGENTS: • Potassium permanganate crystals, finely ground. • Sucrose, or cane sugar • Distilled water • Sodium hydroxide or potassium hydroxide solution. If unavailable, ammonium hydroxide solution may be used as well. PROCEDURE: • Prepare a potassium permanganate solution by adding a tiny pinch of the crystalline perman...

Paracetamol, or acetaminophen, a common painkiller Image courtesy: Google Among the many qualitative analytical tests in organic chemistry, the haloform test, or Lieben's test (specifically, the iodoform test) is quite common. The reagent used for the iodoform test is cold sodium hydroxide solution and iodine mixed together, which react to form sodium hypoiodite. The test detects the presence of an acetyl or an α-hydroxy methyl group. Exhaustive halogenation takes place at the α (methyl) position, which eventually leads to its cleavage as a molecule of haloform. Iodoform, also known as triiodomethane, was once used as an antiseptic but now has been universally replaced, since the antiseptic properties were not characteristic of iodoform itself, but of the iodine liberated from it. It can have an unpleasant odour. Paracetamol, or acetaminophen is a common painkiller that consists of a phenolic ring with an NH-acetyl group at the para position. Due to resonance in the phenolic ring, ...

Alkalis are an extremely important class of chemicals, be it for laboratory or industrial use. Usually they are bought from stores, however, in the event that you are unable to get some, you can always make it at home. This experiment deals with the production of sodium hydroxide solution at home, from the commonly used sodium chloride, or common salt.           The miniature setup of the Castner-Kellner process The cup on the extreme right contains distilled water, while the others contain saturated sodium chloride solution. The cups are connected by cotton soaked in sodium chloride solution, which thus act as salt bridges. If you are performing this experiment, please note that on no account should the concentration of the penultimate cell on the right be less than that of those on its left. Similarly, the second cell from the left should not have a concentration lower than the one on its left. For the electrolysis, I have used a 12V DC adaptor which originall...

You may have heard of the famous explosive 2,4,6-trinitrotoluene, also known as TNT, or 2,4,6-trinitrophenol, commonly called Picric acid. While these explosives may be famous in their own right, it's hard to get your hands on them, and I certainly advise you not to even think about doing so. However, there is another explosive which, albeit less famous, is a greatly shock sensitive compound. It is known as touch powder, or Nitrogen Triiodide. A word of caution: if you are interested in making this, please do so under adult supervision if you do not have enough lab experience. Also, prepare very minute amounts of this compound, because it can be really dangerous. Dry nitrogen triiodide, a purplish black powder . In its completely dry form, the compound is so unstable that it would detonate at the touch of a feather. This is due to the fact that the small nitrogen atom is hardly able to coordinate three large iodine atoms. Thus, the reaction for its dec...