The acidity of phenols can be influenced by other groups linked to the ring . The presence of any substituent on the aromatic ring that can stabilize the phenoxide ion will tend to increase the acidity of the phenol. On the other hand, any substituent that destabilizes the phenoxide ion, increasing its negative charge, will decrease the acidic nature of the phenol. In other words, the presence of electron withdrawing groups in phenols will increase their acidity, while electron density donor groups reduce their acidity .