What happens when washing soda is exposed to the atmosphere

they lose their water

Explanation:

When exposed to air washing soda crystals lose their water of crystallisation and become amorphous. ∴ The phenomenon is called efflorescence.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.