液体表面张力系数测定实验报告.ppt

Abstract Contents Purposes Learn to determine the liquid surface tension coefficient Find out the structure of the Jonly scales and learn to handle it Perceive the phenomenon of liquid surface in deeper ways Principles Image there is a line ss on the liquid level MN, which devides the surface into two parts called A and B. Because of the intermolecular force , there is surface tension on both sides of ss. The intensity of the tension is in proportion to the length of the ss l.That is Principle The moment that the liquid separates from the U-shape wire , the pull F and the surface tension f will approach an equilibrium.so Instruments Instruments Procedures Data table and process Data table and process Discussion The percentage error is 10%. This number is quite large beacause the temperature in the laboratory is unstable The impurities in the water may exaggerate the the surface tension coefficient. Reference * * * * The Determination of Liquid Surface Tension Coefficient by Cao Shuang Liquid as the role of surface tension into the ball with the trend of spontaneous contraction. The value of the surface tension can be described by the surface tension coefficient. In this experiment, the surface tension coefficient is measured by Pulled-off method. Key words: Pulled off method ,Jonly scales ,surface tension coefficient Purpose Pinciple Instruments Procedures Data table and discussion Jonly scale beaker weights alcohol lamp 1 spring 2 counterweight cylinder 3 pointer 4 caliper 5 scale pan 6 objective table 7\9\11 screws 8\10 vernier adjustment knob 12 mirror Install the instrument and adjust it.Began to measure the springs coefficient stubborn Use caliper to measure the width of the wire.And then calculate the surface tension coefficient. Step1 Step2 Step3 Gently hang the burned clean wire under the scale pan.Slowly pull the water film four times.Measure the elongation of the spring in tension Times