How many joules does it take to change 127 grams of water from -15 degrees celsius to boiling?

Idon’t understand this page, can someone ?

Read these sentences from the text. near the equator, the tropics receive the most rain on a consistent basis. as a result, the fresh water falling into the ocean decrease the salinity of the surface water in that region. [. .] . . as the salt content of sea water increases, so does its density. what can you infer about how rain affects the density of surface water near the equator?

Can someone me with these questions plz.