Melting point temperature is a physical belongings of pure substances. It is an intensive belongings. which means the sum of stuff tested is irrelevant. This lab will find the thaw point temperatures of two known pure substances. naphthalene and p-dichlorobenzene. utilizing micro-sized measures and a capillary thaw tubing setup. The per centum mistake will so be calculated by comparing the experimental value to the known literature value. Consequences:
In Table 1 on the following page. it shows the literature value runing points for p-dichlorobenzene and naphthalene. While detecting p-dichlorobenzene’s we noticed it started runing at 54. 6° C ; As for naphthalene we noticed it started runing at 80. 3 ° C. We kept watching closely until p-dichlorobenzene finished thaw or glade at 54. 2° C ( Recorded in Table 2 ) ; Naphthalene finished runing at 80. 9° C. We so used the finishing thaw point and the literature value runing point and plugged it in the % mistake expression. Discussions:
Why should each sample be tightly packed into the capillary tubing prior to proving? Each sample should be tightly packed into the capillary tubing because air infinites affect the thaw point. Why should the heating rate during the runing point findings be every bit slow as 2 to 3 grades C per minute? The warming rate should be every bit slow as 2 to 3 grades Celsius per minute because the thermometer would read more accurately. A slow warming rate allows the transportation of heat from the heating block to the H2O to the thermometer to be more accurate.
What would be the consequence of the presence of an indissoluble dross. such as silicon oxide. on runing point finding? The trial tubing is made of silicon oxide. so the presence of it doesn’t impact the thaw point. If there were pieces of silicon oxide in the trial tubing it might do the thaw point different. if and merely if. the pieces were bi plenty to let air infinites in the trial tubing.