it's becomes a salt water
when we heat the salt there chemical reaction is takes place
Nothing provided the salt is not heated to melting point.
Salt release slowly the heat of dissolution and the temperature is increased.
salt and water are produced, usually with a release of heat.
How salt dissolve in heat
The freezing point of water decrease because the dissolution is a process which release heat.
I assume you are asking why salt melts ice. It's very difficult to tell from your question... What happens, is that ice always has a thin layer of liquid water on it. When salt disolves in water it produces heat, melting the ice, providing more liquid water to disolve the salt into.
Ice is melted over 0 0C and salt is melted over 801 0C.
It give out heat (exothermic) and you get yourselves solution of sodium sulfate salt and water.
The freezing point of water decrease because the dissolution is a process which release heat.
salt
Acid + Basic ----> Salt + Water + Heat