<prompt> Break point chlorination means:Start of chlorination processEnd of chlorination processWhen free residual chlorine starts appearingAfter partial saturation of water with chlorine  <response>: The addition of chlorine to water to a point at which free residual chlorine begins to appear is called breakpoint chlorination.The chlorine demand of the water should be estimated. The chlorine demand of the water is the difference between the amount of chlorine added to the water and the amount of residual chlorine remaining at the end of a specific period of contact at a given temperature and pH of the water.The point at which the chlorine demand of the water is met is called the breakpoint. If further chlorine is added beyond the breakpoint, free chlorine begins to appear in the water.Essentials of preventive and community dentistrySoben Peter5th editionPage number 466 