Question

What does it mean for a weak acid to be in equilibrium?

A) The acids only slightly dissociate and readily undergo reverse reaction.

B)The position of equilibrium in weak acids lies more to the right than to the left.

C)At equilibrium there is a small amount of HA and more A- and H+

D) At equilibrium there is the same amount of HA, A- and H+

Answer 1

A) The acids only slightly dissociate and readily undergo reverse reaction.

for example:

acetic acid
CH₃COOH(aq) ⇄ CH₃COO⁻(aq) + H⁺(aq)

nitrous acid
HNO₂(aq) ⇄ H⁺(aq) + NO₂⁻(aq)

carbonic acid
H₂CO₃(aq) ⇄ H⁺(aq) + HCO₃⁻(aq)
HCO₃⁻(aq) ⇄ H⁺(aq) + CO₃²⁻(aq)