Flavor of the Road
source: http://hubpages.com/hub/Filipino-Trivia---5
Flavor of the Road is the usual description of the Visayans for the ice cream sold by a “sorbetero”. Sorbetero is a Filipino word for an itinerant ice cream vendor. Ever wonder why does he have to add salt to the crushed ice, (on which the ice cream cylinders/containers are submerged)? One might think that probably, he does this to keep the ice cold. Well, it’s true. Adding salt to the ice will even lower the temperature.
Freezing point is one of the colligative properties of solutions. These properties depend on the amount of solute in a solution. What is the effect of the amount of (table) salt to the freezing point of a solution? As more and more solute particles are added, it would be harder for the molecules of water to bond to freeze into ice. Hence, the temperature has to drop lower, such that water molecules are brought closer to bond.
Pure water freezes at zero degree Celsius. Adding 5.85 g of table salt (NaCl) to 100.0 g of water, will result in a freezing point of – 1.86 deg. C. This is the value of the molal freezing point depression constant (Kf) of water. Molal concentration is expressed as the number of moles of solute divided by the kilogram of the solvent.
