Why is it necessary to heat the hydrate gently at first and then more strongly only after most of the water has been driven off

To avoid spattering

Explanation:

If we are heating a hydrate to drive off the water of crystallization, we must initially heat the hydrate gently, at a lower temperature and then more strongly only after most of the water has been driven off in order to to prevent spattering.

Since we obtain the amount of water by the mass difference, Spattering  decreases the mass of water obtained and ultimately results in a lower percent of water being calculated for the hydrate.

i belive it is water

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.