用全反射法测冰醋酸和酒精的折射率

为了研究冰醋酸溶液和酒精溶液的折射率与体积分数的关系，采用全反射的方法测量了不同体积分数的冰醋酸溶液与酒精溶液的折射率，得到了溶液折射率与体积分数的关系曲线。结果表明，冰醋酸水溶液和酒精水溶液的折射率与体积分数均不存在简单的线性关系，而是呈现出类抛物线型的变化关系。开始体积分数随折射率的增大而增大，但在某一中间体积分数处折射率有一最大值，即冰醋酸在体积分数为0.90附近存在最大折射率，酒精在体积分数为0.80附近存在最大折射率。这一结果对于全面认识溶液折射率与体积分数的关系是有帮助的。

Measurement of the refractive indexes of glacial acetic acid and alcohol by means of total reflection

In order to find the relationship between the refractive index and the volume fraction of acetic acid solution and alcohol solution, the principle of optical total internal reflection was chosen to measure the refractive indexes of glacial acetic acid and alcohol with different volume fractions and to obtain their relative curves. The experiments showed that the relationship between the refractive index and the volume fraction of acetic acid solution and alcohol solution was similar to the parabola. It was not the simple linear relationships. The refractive index became larger at the beginning as the solution volume fraction increased, and there was a maximum of the refractive index at a certain volume fraction. Acetic acid solution near the volume fraction of 0.90 and alcohol solution near volume fraction of 0.80 had the maximum refractive indexes respectively. The results are helpful to the comprehensive cognition of the relationship between the refractive index and the solution volume fraction.