In each of the following acid-base reactions, identify the Bronsted acid and base on the left, and their
conjugate partners on the right:
(a) HPO3
2- + HSO3
- → H2PO3
-
+ SO3
2-
(b) C6H5NH3
+
+ OBr-
→ HOBr + C6H5NH2
(c) H2PO3
-
+ CH3CH2CO2H → CH3CH2CO2
-
+ H3PO3
To identify the Bronsted acid and base in an acid-base reaction, you need to understand the concept of Bronsted-Lowry theory. According to this theory, an acid is a substance that donates a proton (H+), and a base is a substance that accepts a proton.
(a) HPO3²⁻ + HSO3⁻ → H2PO3⁻ + SO3²⁻
In this reaction, HPO3²⁻ donates a proton (H+) to HSO3⁻, making HPO3²⁻ the Bronsted acid and HSO3⁻ the Bronsted base on the left side of the reaction. On the right side of the reaction, H2PO3⁻ and SO3²⁻ are the conjugate partners, where H2PO3⁻ is the conjugate base of the Bronsted acid (HPO3²⁻) and SO3²⁻ is the conjugate acid of the Bronsted base (HSO3⁻).
(b) C6H5NH3⁺ + OBr⁻ → HOBr + C6H5NH2
In this reaction, C6H5NH3⁺ donates a proton (H+) to OBr⁻, making C6H5NH3⁺ the Bronsted acid and OBr⁻ the Bronsted base on the left side of the reaction. On the right side of the reaction, HOBr and C6H5NH2 are the conjugate partners, where HOBr is the conjugate base of the Bronsted acid (C6H5NH3⁺) and C6H5NH2 is the conjugate acid of the Bronsted base (OBr⁻).
(c) H2PO3⁻ + CH3CH2CO2H → CH3CH2CO2⁻ + H3PO3
In this reaction, H2PO3⁻ donates a proton (H+) to CH3CH2CO2H, making H2PO3⁻ the Bronsted acid and CH3CH2CO2H the Bronsted base on the left side of the reaction. On the right side of the reaction, CH3CH2CO2⁻ and H3PO3 are the conjugate partners, where CH3CH2CO2⁻ is the conjugate base of the Bronsted acid (H2PO3⁻) and H3PO3 is the conjugate acid of the Bronsted base (CH3CH2CO2H).
Overall, in each reaction, the Bronsted acid donates a proton, and the Bronsted base accepts the proton. The conjugate partners are formed by exchanging the proton between the acid and base.
In order to identify the Bronsted acid and base in each reaction and their conjugate partners, we must first understand the concept of Bronsted-Lowry acid-base theory. According to this theory, an acid is a proton (H+) donor, while a base is a proton acceptor.
Now, let's analyze each reaction step-by-step:
(a) HPO3
2- + HSO3
- → H2PO3
-
+ SO3
2-
In this reaction, HPO3
2- is acting as a Bronsted acid because it donates a proton (H+). HSO3
- is acting as a Bronsted base because it accepts the proton. Therefore:
Bronsted Acid: HPO3
2-
Bronsted Base: HSO3
-
Conjugate Acid: H2PO3
-
Conjugate Base: SO3
2-
(b) C6H5NH3
+ OBr
- → HOBr + C6H5NH2
In this reaction, C6H5NH3
+ is acting as a Bronsted acid because it donates a proton (H+). OBr
- is acting as a Bronsted base because it accepts the proton. Therefore:
Bronsted Acid: C6H5NH3
+
Bronsted Base: OBr
-
Conjugate Acid: HOBr
Conjugate Base: C6H5NH2
(c) H2PO3
- + CH3CH2CO2H → CH3CH2CO2
- + H3PO3
In this reaction, H2PO3
- is acting as a Bronsted acid because it donates a proton (H+). CH3CH2CO2H is acting as a Bronsted base because it accepts the proton. Therefore:
Bronsted Acid: H2PO3
-
Bronsted Base: CH3CH2CO2H
Conjugate Acid: CH3CH2CO2
-
Conjugate Base: H3PO3
So, the Bronsted acid and base, along with their conjugate partners in each reaction, are as follows:
(a) Acid: HPO3
2-, Base: HSO3
- ; Conjugate Acid: H2PO3
-
, Conjugate Base: SO3
2-
(b) Acid: C6H5NH3
+, Base: OBr
- ; Conjugate Acid: HOBr, Conjugate Base: C6H5NH2
(c) Acid: H2PO3
-, Base: CH3CH2CO2H; Conjugate Acid: CH3CH2CO2
-, Conjugate Base: H3PO3