Thermal analysis of a solid-liquid phase using cooling curves at various compositions is a method used to obtain the eutectic composition and temperature of naphthalene-biphenyl. The XE was 0.45 and the TE was 310.3K these are slightly different from the theoretical values which are 0.44 and 312K respectively.
Results
The cooling curves obtained from both groups
Group A
Group B
The table with the mole fraction and the actual masses added. RUN | Group A | Group B | | Naphthalene (g) | Biphenyl added (g) | Biphenyl (g) | Naphthalene added (g) | | target | actual | Mole fraction | target | actual | target | actual | target | actual | Mole fraction | 1 | 2.0 | 2.0 | 0.924 | 0.2 | 0.197 | 2.0 | 2.053 | 0.2 | 0.198 | 0.104 | 2 | | | 0.799 | 0.4 | 0.605 | | | 0.2 | 0.410 | 0.194 | 3 | | | 0.713 | 0.4 | 0.970 | | | 0.2 | 0.604 | 0.262 | 4 | | | 0.605 | 0.6 | 1.570 | | | 0.4 | 1.004 | 0.371 |
The table which shows the thermal breaks and arrests run | Naphthalene (g) | Biphenyl added (g) (Group A) | Biphenyl (g) | Naphthalene added (g) (Group B) | | target | actual | | target | actual | Temperature(K) | target | actual | target | actual | Temperature(K) | | | | | | | break | arrest | | | | | break | arrest | 1 | 2.0 | 2.0 | | 0.2 | 0.197 | 346.9 | - | 2.0 | 2.053 | 0.2 | 0.198 | 333.6 | - | 2 | | | | 0.4 | 0.605 | 337.9 | 308.5 | | | 0.2 | 0.410 | 328.9 | 308.6 | 3 | | | | 0.4 | 0.970 | 331.5 | 311.3 | | | 0.2 | 0.604 | 323.4 | 310.3 | 4 | | | | 0.6 | 1.570 | 322.5 | 311.3 | | | 0.4 | 1.004 | 313.6 | 312.2 |
The phase diagram of naphthalene-biphenyl binary system
Discussion and answers
This experiment is concerned with the thermal analysis of the solid-liquid phase diagram of a binary system. A binary system consists of two metals that may form an alloy or it could be a mixture of naphthalene-biphenyl which are organic compounds. This equilibria
References: Anon., 2009. Lead or Tin Phase diagrams. [Online] Available at: http://www.sanjose.edu/labnotes/tech25 [Accessed 09 April 2013]. Bunnelle, W. H., Meyer, L. A. & Glaser, R. E., n.d. Recrystallization and Melting Point Determination. [Online] Available at: www.chem.missouri.edu/.../Recrystallization%20notes.doc [Accessed 09 April 2013]. Garland, C. W., Nibler, J. W. & Shoemaker, D. P., 2003. Experiments in Physical Chemistry. 7th Edition ed. New York: McGraw-Hill Higher Education.