A Drop-in Replacement for the Antifreeze Ethylene Glycol
Water (with additives to protect against corrosion) circulates between the engine block and the radiator to cool automobile engines. Since water expands on freezing, if the water were to freeze in the engine block of a parked car in a cold-weather climate, severe damage would occur. To prevent this, a chemical antifreeze agent is added to the cooling water to lower the freezing temperature of the mixture; the analysis of freezing-point depression was discussed in Sec. 12.3, from which it is evident that the addition of any solute will lower the freezing point of water. Ethylene glycol is most commonly used. However, some automobile radiators leak, dripping the water + ethylene glycol mixture under parked cars. Because ethylene glycol has a pleasing, sweet taste but is toxic, it has been implicated in the deaths of pet cats.
Your job as a “product engineer” is to find a drop-in replacement for ethylene glycol as an antifreeze agent to ensure that the engine cooling fluid will not freeze at or above −25°C. By the term drop-in replacement, the following is meant. There are more than 100 million cars in current use in the United States, and we are not interested in making major alterations to the automobile engines currently in use; rather, we want something that we can use as a replacement antifreeze that does not require any change to existing automobiles.
