When roads are covered with ice blanket, the car travel becomes more than a hazard. Common salt is used to cover the roadways, which dissolves the ice. It is commonly known that salt melts ice however most of the people are unaware that how does salt melt ice. The following article will help you getting the answer that how does salt melt ice. Some interesting facts about it are that the freezing point of salty oceans is low as compared to fresh water. Salt is added to frozen roadways to make the ice melt. Salt is also used to make ice creams. These all effects are known to people but the how is still undefined.

To define the fact how does salt melt ice you must understand some properties of water, ice and salt. Water is constituted of small molecules, which are always in motion. When the temperature s high the molecules move faster than the usual speed and at low temperature the motion is also lowered down. As the temperature lowers down, the movement of molecules is lowered and molecules come close to each other to make bonds between them.

Normally the freezing point of water is zero degrees centigrade. 0 degrees is the equilibrium point where melting and freezing rate of water is same. On this temperature the ice will remain ice, however, if a foreign substance like salt is added to the ice, it starts melting. The water molecules can't get attached to each other and freezing point of water is lowered down. As the melting rate is unaffected the ice melts at the same rate however forms less quickly. So the melting process continues, converting the ice into water. The salt, which we eat, and the salt of the ocean is actually sodium chloride (NaCl). Sodium chloride, when added to water dissolves in two kinds of ions. One is positively charged sodium ion and the other one is negatively charged chloride ion. These ions surround the water molecules and make it difficult for them to form bonds and convert into ice crystals. Other salts like potassium chloride, ammonium sulfate, calcium chloride and urea also have same effect on ice. But these salts have some negative effects on environment so these are less common than the usual salt, sodium chloride.

Not only the salt but many other substances can disturb the equilibrium point and make the sugar melt such as alcohol and sugar. Salt is usually used because it is abundant and cheap but it still has limited effectiveness. Below -21 degrees the solution becomes saturated and that is of no use.