偶极矩的测定实验数据处理

六、实验数据处理1、计算各溶液的摩尔分数浓度x2.表1、实验数据处理表一序号环己烷质量m1（g)乙酸乙酯质量m2(g)［1］环己烷物质的量n1（mol）乙酸乙酯物质的量n2(mol)摩尔分数x2119.95230.28270.23710.0032080.013218.97701.04150.22550.011820.050317.93682.10870.21310.023930.101416.81963.14080.19990.035650.151515.71804.30200.18680.048830.207计算过程举例：（以序号1为例）已知：环己烷相对分子质量M1=84.16g/mol、乙酸乙酯相对分子质量M2=88.11g/mol。环己烷物质的量n1=m1/M1=19.9523/84.16=0.2371mol乙酸乙酯物质的量n2=m2/M2=0.2827/88.11=0.003208mol溶液的摩尔分数浓度x2=n2/n1=0.003208/0.2371=0.0132、计算环己烷及各溶液的密度ρ溶，作ρ溶—x2图，由直线斜率求算β值。表2、实验数据处理表二摩尔分数x2环己烷的质量m1(g)水质量m2(g)各溶液密度ρ（g/ml)0.0002.30602.98290.77310.0132.31640.77660.0502.32680.78000.1012.33740.78360.1512.34610.78650.2072.35500.7895由表2实验数据作ρ溶—x2图如下：计算过程举例：（纯环己烷为例）ρ环己烷=m环己烷/m水=2.3060/2.9829=0.7731(g/ml)由图1的直线斜率为k=0.0657；根据公式ρ溶=ρ环己烷（1+βx2）：k=βρ环己烷∴β=k/ρ环己烷=0.0657/0.7731=0.084983、作n溶-x2图，由直线斜率求算γ值。表3、实验数据处理表三计算过程举例：（以x2=0.000为例）折射率平均值n=（1.4260+1.4263+1.4261）/3=1.4261由表3实验数据作n溶-x2图，如图3：摩尔分数x2折射率n折射率平均值n0.0001.42601.42631.42611.42610.0131.42511.42491.42501.42500.0501.42311.42301.42291.42300.1011.41901.41891.41891.41890.1511.41551.41621.41621.41600.2071.41261.41241.41241.4125由图2得直线斜率为k=-0.0657；根据公式：n溶=n环己烷（1+γx2）得k=γn环己烷γ=k/n环己烷=-0.0657/1.4261=-0.046074、计算C0、Cd和各溶液的C溶值，求出各溶液的介电常数，作ε溶-x2图，由直线斜率求算α值。已知环己烷的介电常数温度公式为：ε环己烷=2.052-0.00155t实验室温度为t=21.9℃，则：ε标=ε环己烷=2.052-0.00155×21.9=2.018对于环己烷：C’空=5.66PF,C’标=8.19PFCd=（ε标C’空-C’标）/(ε标-1)=(2.018×5.66-8.19)/(2.018-1)=3.17PF因为近似地认为空气与真空电容C0相等，即C空=C0，则：C0=C空=C’空-Cd=5.66-3.17=2.49PF各溶液的介电常数列表如下：表4、数据处理表四计算过程举例：（以x2=0.013为例）实验中测得的C’溶=8.30PF∴C溶=C’溶-Cd=8.30-3.17=5.13PF∴ε溶=C溶/C0=5.13/2.49=2.06由表4实验数据作ε溶-x2图如下：摩尔分数x2C溶（PF）ε溶0.0135.132.060.0505.382.160.1015.772.320.1516.152.470.2076.612.65由上图可得直线斜率：k=3.07根据公式：ε溶=ε环己烷（1+αx2）∴k=αε环己烷∴α=k/ε环己烷=3.07/2.018=1.52