Why do some salts dissolve spontaneously even though the process is endothermic overall?

Ineed with a, b, c, d, and e on the long answer

Harvey kept a balloon with a volume of 348 milliliters at 25.0˚c inside a freezer for a night.  when he took it out, its new volume was 322 milliliters, but its pressure was the same.  if the final temperature of the balloon is the same as the freezer’s, what is the temperature of the freezer? the temperature of the freezer is  kelvins.

In saturated organic compounds, all the bonds between carbon atoms are called?