In Medical field, phenol was first used as an antiseptic by Joseph Lister.Joseph Lister was a student at University College London under Robert Liston, later rising to the rank of Surgeon at Glasgow Royal Infirmary. He believed that patients who passed through surgery, died due to infections caused by microorganisms.He theorized that if germs could be killed or prevented, no infection would occur. Lister reasoned that a chemical could be used to destroy the micro-organisms that cause infection. He made use of the carbolic acid by soaking a clean cloth in them, and placing it over the surgical wounds of patients.
Equilibrium means the state of reaction which there is no net changes occur it means the rate of forward reaction and rate of backward reaction become same and also it does not mean that the concentration of both side i.e. reactant and product become equal. after gaining equlibrium position the concentration of reactant and product remain same and also chemical reaction does not stop and it continues.