text: At equilibrium the rate of the forward reaction is equal to the backward reaction rate. A simple reaction, such as ester hydrolysis
  has reaction rates given by expressions
  According to Guldberg and Waage, equilibrium is attained when the forward and backward reaction rates are equal to each other. In these circumstances, an equilibrium constant  is defined to be equal to the ratio of the forward and backward reaction rate constants  
  The concentration of water may be taken to be constant, resulting in the simpler expression 
  This particular concentration quotient, , has the dimension of concentration, but the thermodynamic equilibrium constant, , is always dimensionless.