The answer is 3). This is because elements are the simplest form of a substance, and cannot be broken down any further. Compounds on the other hand are much more complex than elements and can be broken down INTO elements.
For example, Na, sodium, is an element and cannot be broken down further. H2O, water, is a compound and can be broken down into Hydrogen and Oxygen.
K is Potassium
Cl is Chlorine
There are 2 elements.
The final temperature of the water will be 31.2 °C... i don’t know the second one sorry :(
The ammonia gas is absorbed in the concentrated brine to produce aqueous sodium chloride and aqueous ammonia. This ammoniation process is exothermic, so energy is released as heat. The ammonia tower eventually needs to be cooled.