Question

When NaCl (table salt) dissolves in water, the change is endothermic. Yet, when added to water, it
dissolves without added energy (spontaneously) over a wide range of temperatures. How can this
be?

Answer 1

Hello there, mate!  

This happens because of the fact that endothermic reactions result as a positive ΔH. Then, when the NA-Ci chemical is added to the water, the water's thickness and entropy increases, which causes ∨-salt ions to start forming in the water (ω).