Question

What is the chemical equation for titration of `HCl + NH_3`?

Answer 1

`"NH"_ (3(aq)) + "HCl"_ ((aq)) -> "NH"_ 4"Cl"_ ((aq))`

Explanation:

Hydrochloric acid, `"HCl"`, a strong acid, will react with ammonia, `"NH"_3`, a weak base, to form aqueous ammonium chloride, `"NH"_4"Cl"`, according to the following chemical equation

`"NH"_ (3(aq)) + "HCl"_ ((aq)) -> "NH"_ 4"Cl"_ ((aq))`

In this particular reaction, the chloride anions, `"Cl"^(-)`, act as spectator ions, which means that you can eliminate them from the balanced chemical equation to get the 8net ionic equation*

`"NH"_ (3(aq)) + "H"_ ((aq))^(+) -> "NH"_ (4(aq))^(+)`

It's worth mentioning that because you're titrating a strong acid with a weak base, the pH of the resulting solution will be lower than `7` at equivalence point.

That is the case because this neutralization reaction produces the ammonium cation, `"NH"_4^(+)`, which acts as a weak acid in aqueous solution.

Assuming that you're running ammonia into hydrochloric acid, the titration curve will look like this