05_Prerequisites

Do you know salt actually plays a very important role in the making of an ice-cream? Yes, salt is used in the making of ice-cream. This is because, # # So, basically salt lowers the freezing point of ice and if ice is kept in salt water the ice melts slowly, since the lower temperature of the mixture would mean a lower rate of melting or more chances of molecules tolling at one place. Let us understand this through an activity. We need salt, two glasses of water and two ice cubes. Add some salt in one glass and stir it well. Now put ice cube each in salt water as well as pure water. Wait for sometime and remove both the ice cubes. Check their sizes. We find that the ice cube taken out from salt water has melted less than that in pure water. So, this proves that ice in salt water melts slowly. Before, the invention of refrigeration, and even today in many areas, ice-creams are distributed in insulated vessels, with salt and ice mixture, this keeps the ice-cream frozen, for almost the entire day.