Question

Identify the conjugate acid-base pairs in each of the following equations:

1) HF(aq)+CO32?(aq)?F?(aq)+HCO3?(aq)

Check all that apply.

a) F?/HCO3?

b) HF/F?

c) HF/CO32?

d) HCO3?/CO32?

2) HCl(aq)+OH?(aq)?Cl?(aq)+H2O(l)

a) HCl/OH?

b) HCl/Cl?

c) H2O/OH?

d) H2O/Cl?

Answer 1

Conjugate acid base :

Lets first look at conjugate acid

The base when gets proton is becomes conjugate acid

Conjugate base:

When acid give its proton and forms species that is called as conjugate base.

Q. 1^st

In this question, HF is an acid which gives its proton and form F-

So F- is conjugate base of HF

CO₃^-2 is base which takes proton from HF and forms HCO3^- so HCO3^- is conjugate acid of CO₃^-2

So the answer for this question is

d : d) HCO3−/CO32−

Q. 2^nd

HCl(aq)+OH−(aq)→Cl−(aq)+H2O(l)

Here HCl is acid and its conjugate base is Cl-

OH- is base and its conjugate acid is H2O

So the answer is

d) H2O/Cl−

Answer 2

Conjugate acid/base pairs differ each other by a single proton unit. Coser the given reacton netfes by s proton as shown below: HF (aq) + COÇ (aq) F (aq) + HCO, (aq) HF is an acid which is losing a proton to form F ion, acting as a conjugate base of HIF Similarly, CO;-is a base which is taking up a proton to form HCO-, considered as a conjugate acid of co Hence, the conjugate acid base pair in the given reaction is, HCO/C conjugate acid Thus, the correct option is d 2. HCl(aq)+OH (aq)Cl (aq)+H2O(l) HCl is an acid which is losing a proton to form Cl ion, acting as a conjugate base of HCI Similarly, OH is a base which is taking up a proton to form H,O, considered as a conjugate acid of OH Hence, the conjugate acid base pair in the given reaction is. H2O /OH conjugate base acid Thus, the correct option is C