Question #ee8bb

1 Answer
Jul 21, 2017

Answer:

Yes, it is.

Explanation:

Ammonium nitrate is indeed an acidic salt. Here's why.

Ammonium nitrate is soluble in water, which implies that it dissociates completely in aqueous solution to produce ammonium cations, #"NH"_4^(+)#, and nitrate anions, #"NO"_3^(-)#.

#"NH"_ 4"NO"_ (3(aq)) -> "NH"_ (4(aq))^(+) + "NO"_ (3(aq))^(-)#

Now, the ammonium cation acts as a weak acid in aqueous solution, meaning that it can donate its proton to a water molecule to form hydronium cations, #"H"_3"O"^(+)#, and ammonia, #"NH"-3#, a weak base.

#"NH"_ (4(aq))^(+) + "H"_ 2"O"_ ((l)) rightleftharpoons "NH"_ (3(aq)) + "H"_ 3"O"_ ((aq))^(+)#

Since the presence of the ammonium cations in solution causes an increase in the concentration of the hydronium cations, which, consequently, causes the #"pH"# of the solution to decrease compared with that of pure water at the same temperature, you can say that ammonium nitrate is an acidic salt.

In fact, the #"pH"# of an ammonium nitrate solution at room temperature is equal to #5.25# #-># see here for more info on that.

Also, note that the nitrate anion does not hydrolyze because nitric acid si a strong acid, which implies that the nitrate anion cannot accept a proton from a water molecule

#color(red)(cancel(color(black)("NO"_ (3(aq))^(-) + "H"_ 2"O"_ ((l)) -> "HNO"_ (3(aq)) + "OH"_ ((aq))^(-))))#