The excess molar volume, excess speed of sound, excess isentropic compressibility, excess thermal expansion, and excess refractive index (RI) were determined from measurements of density, speed of sound, and RI for the systems of n-heptane (1) + pentan-2-one (2)/4-methylpentan-2-one (2) in the temperature range of 298.15–338.15 K and at an atmospheric pressure of 0.101 MPa. The density, speed of sound, and RIs of the mixtures were nonlinear and decreased with increasing temperature. The excess volume was found to increase with temperature, with the maxima at approximately x₁ = 0.6 mole fraction. Relevant excess properties were fitted using 5-parameter Redlich–Kister expansions and were mostly correlated within experimental uncertainty.

中文翻译：

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T = 298.15–338.15 K和0.101 MPa时正庚烷与Pentan-2-one或4-甲基戊烷-2-one混合物的密度，声速和折射率测量

从正庚烷（1）+戊烷体系的密度，声速和RI的测量结果确定了过量的摩尔体积，过量的声速，过量的等熵压缩性，过量的热膨胀和过量的折射率（RI）-2-one（2）/ 4-methylpentan-2-one（2）在298.15–338.15 K的温度范围内和0.101 MPa的大气压下。混合物的密度，声音速度和RIs是非线性的，并且随着温度的升高而降低。发现过量的体积随温度增加，最大值大约为x ₁ = 0.6摩尔分数。使用5参数Redlich-Kister展开拟合了相关的多余属性，并且它们大多在实验不确定性内相关。