Remarkably, they have an aqueous path that passes water without being permeable to the common ions. Ion channels are involved in every thought, every perception, every movement, every heartbeat.

The addition of NH 4 Cl to a solution of ammonia shows the effect of adding a common ion to a system at equilibrium.

Solutions must be kept basic (pH>8). Gloves are necessary to prevent absorption through the skin. Nickel salts are poisonous if ingested. Ammonia and ethylenediamine are caustic and irritating to skin ...