Answer:
B is a stronger base than A^-, which is a stronger base than H2O, which is a stronger base than CI^-
Explanation:
The general equation for each acid is:
HA(aq) + H2O(ac) ⇄ H3O+(aq) + A-(aq)
HB(aq) + H2O(ac) ⇄ H3O+(aq) + B-(aq)
When these acids dissociate into its ions in water they lose a proton (H+), so they are proton donors (acids) and H2O is the proton acceptor (base). This reaction produces a conjugate acid and a conjugate base.
Conjugate base is what remains of the acid molecule after it loses a proton:
HA = acid A- Conjugate base
HB = acid B- Conjugate base
A conjugate acid is formed when the proton is transferred to the base
H2O = base H3O+ = Conjugate acid
The stronger acid will produce a weaker base. According to this, if HA is a stronger acid than HB, A- would be the weaker base (B- is the stronger base).
Compared with water, A- and B- are stronger bases because when they compete for a proton they have much greater affinity for H+ than water does and the equilibrium position will lie far to the left. (HA and HB are weak acids)
Finally Cl- is the weakest base because it comes after dissociation of HCl which is a strong acid
HCl(aq) + H2O → H3O+(aq) + Cl-(aq)
Note there is no double arrows, equilibrium lies far to the right. A strong acid yields a weak conjugate base it means one that has a low affinity for a proton.
