6A.9 a

[Gabriella Bates 2L]

Which of the following can be classified as reactions between Brønsted acids and bases? For those that can be so classified, identify
the acid and the base. (Hint: It might help to write the net ionic equations.) (a) NH4I(aq) + H2O(l) -> NH3(aq) + H3O1(aq) + I2(aq)

Would the acid in this case be NH4+ or NH4I? Thanks!

[Harry Zhang 1B]

The chemical equation is not balanced(The I2 should be just I^-(aq)). After correcting this, writing the net ionic equation, the I^- ions will cancel out and the species left are NH4+,H2O,H3O^+,NH3. Since the proton donator is NH4+, NH4+ is the bronsted acid.

[DesireBrown1J]

The chemical equation is not balanced(The I2 should be just I^-(aq)). After correcting this, writing the net ionic equation, the I^- ions will cancel out and the species left are NH4+,H2O,H3O^+,NH3. Since the proton donator is NH4+, NH4+ is the bronsted acid.

Why would it be NH₄+ as the acid instead of NH₄I? And how did you get NH₄+ from this equation?

[Harry Zhang 1B]

This is because NH4I will dissociate in water and the definition of a bronsted acid is a proton donor and NH4+, being a strong conjugate acid of a weak base NH3, will donate its proton to the water molecule. On the other hand, I- is the weak conjugate base of a strong acid HI and will not affect the pH level of water.