# Conjugate bases

Amy-Lee

## Homework Statement

Indicate the conjugate bases of the following:

NH2-
NH2-

## The Attempt at a Solution

This is the only information given. Can I assume that these species react with water? The ionic signs indicate that they are bases, but are they the conjugate bases?

Mentor
What are the definitions of acid and conjuagte base? Can you write acid-base reaction equation involving one of given ions as a reactant and the other as a product?

--
methods

Amy-Lee
When species donates a proton, it becomes the conjugate base; when a species gains a proton, it becomes a conjugate acid...

NH2- + H2O -> NH3 + OH-

NH2- becomes a conjugate acid

PhaseShifter
When species donates a proton, it becomes the conjugate base;

What does $$NH{_2}{^-}$$ become when it donates a proton?

Amy-Lee
what does $$nh{_2}{^-}$$ become when it donates a proton?

nh ?

PhaseShifter
nh ?
Close, but still missing something.

What will the charge be?

Amy-Lee
Close, but still missing something.

What will the charge be?

negative

Amy-Lee
So is the conjugate base of NH2- N3-?

Mentor
No, acid and conjugate base must differ by exactly one proton. And PhseShifter didn't ask about positive/negative, but about exact value. You wrote nh (meaning NH) - but what is the exact charge?

--
methods

Amy-Lee
No, acid and conjugate base must differ by exactly one proton. And PhseShifter didn't ask about positive/negative, but about exact value. You wrote nh (meaning NH) - but what is the exact charge?

NH-

Mentor
Oops, sorry, somehow I missed track of hydrogens and charge

So is the conjugate base of NH2- N3-?

That was right. I misread it as NH2-, not NH2-.

Still, nh was wrong - should be NH2-. Treat my mistake as a warning why you should never ignore capitalization and charge - it adds to the confusion.

--

Amy-Lee
I will, thank you so much for all your help and patience.