the romance of Tristan and Iseult
Most people do not realize the fact that chemical processes occur when an egg boils. The reason is that they simply want the egg to cook so that they might eat it in a timely manner. However, the chemical processes by which cooking is completed can be a very interesting subject. “To many, chemistry is little more than an arcane form of cooking. Synthetic chemists may recoil in horror at such a description, but the appearance of microwave ovens in the laboratory hints that there may be more to this analogy than meets the eye. For a start, using microwave energy can significantly reduce reaction times for many syntheses” (Cresswell and Haswell, 621). When the egg is cooked in the water, it is brought to a ‘boiling point’. In this case, the boiling point means that the temperature at which the vapor pressure of a liquid is equal to the external pressure on the liquid. The standard boiling point is the temperature at which the vapor pressure of a liquid is equal to the standard pressure. Many people believe that adding salt to the water will increase the temperature and, thus, cause food to cook faster. What basically happens is that “the nonvolatile solute molecules are seen as partly blocking the escape of solvent molecules from the surface of the solution. In order to heat the solution, the temperature must be raised to once again make the solution vapor pressure equal to the external pressure exerted by the atmosphere upon the surface of the solution. While this explanation sounds interesting, it gives a very ambiguous picture for what real ionic solutions look like. Ionic salts, such as NaCl, are only soluble in water because the energy of solvation of the ions is almost as large as the enormous energy associated with the Coulombic attraction of the positive and negative ions in the crystal. Due to this strong solvation, one would basically never find a Na(+) or Cl(-) sitting on the surface of the solution since it would not have its full solvation shield of water molecules around it. In essence, the surface of even a highly concentrated salt solution is pure water. It is certainly true that a small increase in cooking temperature can extensively increase the rate of cooking; cooking times will normally be only half as long if the water temperature is raised by 10 to 20 C. However, even if we make the cooking water as salty as sea water, which requires adding twelve tablespoons of table salt per gallon of water, the boiling point will only increase by 0.6 C which will only decrease the cooking time by a few percent” (Lehmann Internet source). The need for a chemical approach to cooking is a modern one and is connected to the manufacturing and distribution of food on an industrial level.