Freezing Point Of Naphthalene :: essays research papers

Freezing Point of NaphthaleneI.PurposeTo determine the halt point of a known substance, naphthaleneII.Materials visitstandgas sourcetest pipetest tube clampsthermometer naphthaleneBunsen burner goggleshosestopwatchIII. mental process1.Assemble the Bunsen burner, attaching one end of the hose to theburner and theother to a gas source.2.Assemble the ring stand so that a ring clamp is attached to thestand holding thetest tube that forget be used in the experiment.3.Fill the test tube to or so 1/8 capacity withnaphthalene crystals.4. Place the thermometer in the crystals so that it is surroundby the naphthalenepowder but not touching the sides or tail assembly of the test tube.Use a clamp to holdthe thermometer in place.5. break through the Bunsen burner and using direct heat pass off thenaphthalene powder untilit entirely turns to a liquid. When the temperature reachesapproximately 90oCelsius, stop heating.6.Observe the change in temperature from 90o to 70o Celsius,transcript ion thetemperature at regular intervals, preferably 15 seconds. Thisdata will be used tomake a chart later.7.Once the temperature has fallen to 70o, melt the naphthalenewhich is nowfrozen to remove the thermometer. Properly dispose ofthe naphthalene liquid asinstructed by the teacher.IV.DataTime ElapsedTemperature of NaphthaleneTimeTemperatureInitial (000)100oC70078.5oC03097.5oC71578.3oC10093.0oC73078.3oC13089.5oC74579.0oC20086.1oC80079.0oC23084.6oC81579.0oC24582.3oC83079.0oC30081.2oC84579.0oC31581.0oC90079.0oC33080.5oC91578.5oC34580.2oC93078.1oC40080.0oC94578.0oC41579.9oC100078.0oC43079.8oC101577.5oC44579.4oC103077.0oC50079.1oC104576.5oC51579.1oC110076.0oC53079.0oC111575.2oC54578.9oC113073.8oC60078.8oC114573.0oC62578.8oC120072.1oC63078.7oC121571.1oC64578.6oC123070.3oCV.Graph(See following pages)VI.CalculationsUsing 80.1 oC as the theoretical value for the freezing point ofnaphthalene, we can nowdetermine percent error. portion misapprehension = ((Theoretical - Experimental) / The oretical) x 100Percent Error = ((80.1 oC - 79.0 oC) / 80.1oC) x 100Percent Error = 1.4%VII.ConclusionsIn this lab, we heated the known substance naphthalene in a test tube toapproximately 100oC and observed its temperature while it cooled toapproximately 70oC. everywhere a time period of 12 minutes and 30 seconds, we savethe temperature at regular 15 second intervals, and, with this data, constructeda chart presentation the general curve. Upon inspection of the graph and our datachart, we found the experimental freezing point of naphthalene to be around 79oC.