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

An acid-base indicator is a substance that changes color as the pH of the solution changes. Indicators work because they are weak acids which when in solution, exist in equilibrium with their ...

This is called an equilibrium and is present in water and ... Adding water to an acid or base will change its pH. Water is mostly water molecules so adding water to an acid or base reduces the ...