History of organic chemistry. Characteristic features of organic compounds
In the early 1800s chemists sorted substances into two groups by where they came from: those obtained from rocks and minerals, and those from plants and animals (organic substances); the second group was thought to arise only in living organisms under a special “vital force”. Laboratory syntheses disproved this: F. Wöhler made oxalic acid from dicyan in 1824 and urea from ammonium cyanate in 1828; A. Kolbe synthesized acetic acid, M. Berthelot a fat, and A. M. Butlerov a sugar-like substance from formaldehyde. Organic chemistry is the science of the structure, preparation and properties of hydrocarbons and their derivatives. Organic compounds are distinguished by carbon atoms joining each other and other elements by covalent bonds into long chains. They burn to give CO₂ and H₂O, melt and decompose more easily than inorganic salts, mostly do not dissociate into ions in solution (non-electrolytes), and their reactions are usually slow. Another feature is isomerism: substances with the same composition but different structure exist.
Split the class into two teams and play “inorganic or organic?”: one team writes names of everyday materials (sugar, table salt, cotton, glass, vinegar, candle wax) and the other guesses their class from what they know about burning and solubility. Nothing is burned — work only with pictures and names.