Which of the following pairs are conjugate pairs ?
1) H+ and OH-
2) HCl and Cl-
3) NH2- and NH4+
4) H2SO4 and SO4^-2
thanks a lot
To determine whether pairs of ions are conjugate pairs, we must understand the concept of conjugate acid-base pairs.
Conjugate acid-base pairs are related to each other through the transfer of a proton (H+ ion). In an acid-base reaction, an acid donates a proton, while a base accepts that proton. The acid that donates the proton is called the conjugate acid, and the base that accepts the proton is called the conjugate base.
So, to identify conjugate acid-base pairs, we need to find an acid and its corresponding base (or vice versa) that differ by only one proton.
Let's analyze the given pairs:
1) H+ and OH-
++ These are not conjugate pairs because H+ does not have a conjugate base, and OH- does not have a conjugate acid.
2) HCl and Cl-
++ HCl is an acid, so its conjugate base will be Cl-. Thus, HCl and Cl- are conjugate acid-base pairs.
3) NH2- and NH4+
++ NH2- is the conjugate base of NH4+, and NH4+ is the conjugate acid of NH2-. Therefore, NH2- and NH4+ are conjugate acid-base pairs.
4) H2SO4 and SO4^-2
++ H2SO4 is an acid, but SO4^-2 is not its conjugate base. The conjugate base of H2SO4 is HSO4-, not SO4^-2.
Therefore, the conjugate acid-base pairs from the given options are:
- HCl and Cl-
- NH2- and NH4+