Densities and excess volumes of binary mixtures of N,N-dimethylformamide with aromatic hydrocarbon at different temperature

Density of three binary mixtures formed by N,N-dimethylformamide (DMF) with aromatic hydrocarbon (one of benzene, toluene, and ethylbenzene) has been determined over the full range of compositions at the temperatures range (293.15 to 353.15) K and atmospheric pressure using a vibrating-tube densimeter. From these experiments, excess molar volumes (VmE) could be calculated and fitted by the fourth-order Redlich–Kister equation, so the coefficients and the standard error (σ  ) could be got. Our result shows VmE decreases when temperature increases in the studied systems.