Conjugate Acids and Bases

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Joined: Sat Aug 17, 2019 12:15 am

Conjugate Acids and Bases

How can you tell if compounds are conjugate acids or bases? Will they always both be in the chemical equation?

Sahil Jog 1F
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Re: Conjugate Acids and Bases

A general guidline to figure out conjugate acids and bases would be to draw the formula out and first identify the acids and bases involved in the reaction. Then, looking at the products, the product of the acid would be its conjugate base and the product of the base would be its conjugate acid. For example, in the following reaction: NH2NH3+ + H20 <====> NH2NH2 + H30+ NH2NH3+ would be the acid, H20 the base, NH2NH2 the conjugate base, and H30+ the conjugate acid.

Claire Lo 3C
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Re: Conjugate Acids and Bases

Conjugate acids and bases are bronsted acids and bases. They always appear in the same chemical reaction.

Brandon Valafar
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Re: Conjugate Acids and Bases

The best way to tell is to write out the equation and gauge which is an acid and base in the reactants and bases. Yes, the conjugate acids and bases will always be in the equation.

nickianel_4b
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Joined: Thu Jul 25, 2019 12:17 am

Re: Conjugate Acids and Bases

My TA wrote this on the board in discussion:
HA + B --> A- + BH
parent acid + parent base --> conjugate base + conjugate acid

So yeah writing out the equation is helpful because then you can more easily see how the role of conjugate acid/base relates to the movement of the H+.

Cassandra_1K
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Joined: Wed Sep 18, 2019 12:16 am

Re: Conjugate Acids and Bases

Yes there will always be a conjugate acid and conjugate base so long as there is both an acid and a base.

Michelle N - 2C
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Joined: Wed Sep 18, 2019 12:19 am

Re: Conjugate Acids and Bases

Here's how I work through a problem when identifying acids, bases, conjugate acids, and conjugate bases. Hope this helps you as well, and let me know if there's another method that's more helpful to know:

- I know that an acid in general is either a H+ donor or an e- pair acceptor, and that a base in general is either a H+ acceptor or an e- pair donor.
- Knowing that, I can then extend on that fact that a conjugate acid would be where a molecule either gains an H+ or loses an e-, and that a conjugate base is where a molecule either loses an H+ or gains an e-.
- When I look at the formula, I look at the reactant and it's equivalent product. If the product looks like it lost a H+, then I know that the product is a conjugate base, and the reactant for it was an acid.

So, to answer your question, it seems like it's present in every chemical equation involving them.