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'''Vapor Pressure Lab''' ''Introduction'' *<b>Vapor pressure</b> is the <b>pressure exerted by the vapor particles (in the gas phase) above a liquid layer</b> (the system must be closed, in other word, the container is sealed). *Vapor pressure is directly related to the intermolecular force (IMF) keeping the liquid molecules held together. Therefore, the <b>higher the IMF</b>, the <b>less amount of vapor particles are in the gas phase</b>, and therefore, the <b>lower the vapor pressure.</b> *<b>Boiling point</b> is the <b>temperature</b> where the <b>vapor pressure = atmospheric pressure.</b><br> <b>Boiling point</b> is a function of <b><nowiki>IMF</nowiki></b> and <b><nowiki>MW</nowiki></b>, molecular weight or molar mass. *In this lab, we will look at the intermolecular forces in the substance to predict which substance has the highest vapor pressure (thereby determining which has the greater boiling point). <b>Procedures</b><br> At your desk, determine the molecular polarity of hexane (C<sub>6</sub>H<sub>14</sub>) and water.<br> <br> <br> <br> <br><b>In the lab</b><br> *Get a test tube rack and two large test tubes. *Get two large balloons (do not do anything with balloons especially blow them up) *Get a 250ml beaker and fill it with approximately 150ml of tap water. *Turn on heating element and place 250ml beaker on heater. *In one large test tube, add approximately 2ml (w/pipette) of hexane and then place balloon over top of test tube making sure to take all air out of balloon. *In the other large test tube, add approximately 2ml (w/pipette) of water and then place balloon over top of test tube making sure to take all air out of balloon. *Make observation of the condition of the balloon. *Let heating element heat up the water bath & both of the test tubes (once boiling starts shut off heating element). Periodically, make observations on the condition of the balloons. *When done heating system, remove (once beaker is cool to touch) the 250ml beaker with test tubes from the heating element and let it cool on the table top. *Observe the condition of the balloons after the water has cooled back down to room temperature. <br> <br> <b>Data Table</b> <br> *Initial observation of balloons in water bath: <br> *Periodic observation of balloons: <br> *Final observation of balloon after cooling back to room temperature. <br> <b>Questions</b> <br> <br> *Which substance has the higher vapor pressure and how did you know it? <br> *Did your results agree with what you predicted?
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