6A.9 a

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Gabriella Bates 2L
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Joined: Thu Jul 11, 2019 12:15 am

6A.9 a

Postby Gabriella Bates 2L » Sun Dec 01, 2019 5:13 pm

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
Posts: 101
Joined: Sat Sep 14, 2019 12:16 am

Re: 6A.9 a

Postby Harry Zhang 1B » Sun Dec 01, 2019 5:24 pm

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
Posts: 98
Joined: Wed Sep 18, 2019 12:18 am

Re: 6A.9 a

Postby DesireBrown1J » Sun Dec 01, 2019 10:24 pm

Harry Zhang 1D wrote: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
Posts: 101
Joined: Sat Sep 14, 2019 12:16 am

Re: 6A.9 a

Postby Harry Zhang 1B » Fri Dec 06, 2019 9:02 am

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.


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