Mass densities of dilute aqueous solutions of 1-butanol and 1-pentanol (with alcohol concentrations between 0.07 to 0.7 and 0.006 to 0.06 mol·kg^–1, respectively) were determined at atmospheric pressure and temperatures in the range of 283.15 to 353.15 K using a custom-built volume dilatometer. The dilatometer was first calibrated using water, and it was then benchmarked using water and aqueous solutions of ethanol. Evaporation in the experiments with water and the alcohol solutions was prevented by adding a small amount of oil (about 0.2 mL) over the liquid surface that was exposed to the ambient air. The density data complement and extend those available in the published literature. They also show that at alcohol concentrations less than 0.01 mol·kg^–1, the density of such solutions may be reasonably assumed to be the same as that of water or calculated using the ideal-solution assumption. For solutions with higher alcohol concentrations, however, the aforementioned assumptions are inappropriate, as they lead to density values that differ from the data presented in this paper by amounts that exceed the expanded uncertainty of the underlying measurements.

中文翻译：

---

1-丁醇和1-Pentanol稀水溶液在常压和283.15至353.15 K范围内的温度下的密度

在大气压和温度范围为283.15至353.15 K的条件下，测定1-丁醇和1-戊醇稀水溶液（醇浓度分别为0.07至0.7和0.006至0.06 mol·kg ^–1）的质量密度。定制的体积膨胀仪。首先使用水对膨胀仪进行校准，然后使用水和乙醇水溶液对其进行基准测试。通过在暴露于环境空气的液体表面上添加少量油（约0.2 mL），可以防止水和醇溶液在实验中的蒸发。密度数据补充并扩展了已发表文献中的可用数据。他们还表明，在酒精浓度小于0.01 mol·kg ^{–1的情况下}，可以合理地假设此类溶液的密度与水的密度相同，或使用理想溶液的假设进行计算。但是，对于酒精浓度较高的溶液，上述假设是不合适的，因为它们导致的密度值与本白皮书中的数据相差超出了基础测量结果的扩展不确定性的量。