the results of the experiment on heating 1,1,1-trichloroethane are plotted on a graph (figure 1.17). the temperature increases until the liquid boils at 47. this is the boiling point of 1,1,1-trichloroethane. heat energy is absorbed by the particles of the liquid during boiling. it is used io break all the forces holding the particles together. that is why the temperature remains constant during boiling (line AB on the graph).