A  CL = KCL by definition and it is called the Beer Lambert Law. A = KCL K = Specific Extinction Coefficient - 1 g of solute per liter of solution A = ECL E = Molar Extinction Coefficient - Extinction Coefficient of a solution containing 1g molecule of solute per 1 liter of solutionA  CL = KCL by definition and it is called the Beer Lambert Law. A = KCL K = Specific Extinction Coefficient - 1 g of solute per liter of solution A = ECL E = Molar Extinction Coefficient - Extinction Coefficient of a solution containing 1g molecule of solute per 1 liter of solution