Write the conjugate acids for the following Brönsted bases : NH2-, NH3, HCOO-
NH3, NH4+, HCOOH
Understanding Brönsted-Lowry Acid-Base Theory
The Brönsted-Lowry theory defines an acid as a proton (H+) donor and a base as a proton acceptor. When a Brönsted base accepts a proton, it forms its conjugate acid. Conversely, when a Brönsted acid donates a proton, it forms its conjugate base.
To find the conjugate acid of a given Brönsted base, we simply add one proton (H+) to the base. The charge of the resulting species will increase by +1.
Finding the Conjugate Acids for Given Brönsted Bases
Let's find the conjugate acid for each of the given Brönsted bases: NH2-, NH3, and HCOO-.
- For the base NH2-:
Adding a proton (H+) to NH2-:
\(\text{NH}_2^- + \text{H}^+ \rightarrow \text{NH}_3\)
The conjugate acid of NH2- is NH3.
- For the base NH3:
Adding a proton (H+) to NH3:
\(\text{NH}_3 + \text{H}^+ \rightarrow \text{NH}_4^+\)
The conjugate acid of NH3 is NH4+.
- For the base HCOO-:
Adding a proton (H+) to HCOO- (formate ion):
\(\text{HCOO}^- + \text{H}^+ \rightarrow \text{HCOOH}\)
The conjugate acid of HCOO- is HCOOH (formic acid).
Comparing Results with Options
We found the conjugate acids for the given Brönsted bases in the order NH2-, NH3, HCOO- to be NH3, NH4+, and HCOOH.
Let's look at the options provided:
- Option 1: NH3, NH4+, HCOOH
- Option 2: N3-, NH3, \(\rm HCO^-_2\)
- Option 3: NH4+, NH3, CO2
Comparing our calculated conjugate acids (NH3, NH4+, HCOOH) with the options, we see that Option 1 matches our results exactly in the correct order corresponding to the given bases.
Therefore, the conjugate acids for NH2-, NH3, HCOO- are NH3, NH4+, HCOOH respectively.
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