What does it mean for a weak acid to be in equilibrium? the acids only slightly dissociate and readily undergo reverse reaction. the position of equilibrium in weak acids lies more to the right than to the left. at equilibrium there is a small amount of ha and more -a and +h at equilibrium there is the same amount of ha, mc014-3.jpg and mc014-4.jpg.

When a weak acid is said to be in equilibrium, it means that the acid is only slightly dissociates and will readily undergo reverse reaction. This readiness to undergo reverse reaction is denoted by two arrows which face opposite direction. When a weak acid is added to water, a homogeneous equilibrium forms in which aqueous acid molecules react with liquid water to form aqueous hydronium ion and aqueous anions. 

The answer is b because c don't explain why the moths are on them and it isn't a because as we know only one species of moth does this