Determination of the Solid-Liquid Phase Diagram for Napthalene-Biphenyl Using Thermal Analysis

The first part of the lab began by one lab member adding 10.0 mL of DI water to a test tube while another lab member obtained a beaker full of ice and salt. After both these steps were complete the test tube was put in the beaker full of ice. Immediately following the test tube be being placed in the beaker, a temperature probe was inserted into the test tube. The initial temperature was recorded and after the temperature was recorded in 30 second increments. Once the water exhibited supercooling and then remained consistent at .1 °C for 3 readings it was determined that the water had froze and formed crystals. Evidence that crystals formed allowed for it to be confirmed that the water actually hit freezing point at .0

The freezing point depression constant for water that was experimentally determined in this analysis was 0.0479 °C/m, which was derived from the slope of the trend line in Figure 4. This is significantly lower than the constant stated in the literature of 1.86 °C/m.1 The freezing point temperature determined via cryoscopy should have been much lower in the high sucrose concentration solutions.

After each of the solids were completely dry, each was placed into a MelTemp device. The temperature at which each solid began to melt and completed melting was recorded.

The freezing point constant (Kf) of water is 1.86 °C m-1. Each mass amount and Van’t Hoff factor was calculated then analyzed in a table.

melting produced a drop in pipette readings. For each gram of ice that melted, the volume change

The reaction "ICE" table demonstrates the method used in order to find the equilibrium concentrations of each species. The values that come directly from the experimental procedure are found in the shaded regions. From these values, the remainder of the table can be completed.

Purpose: The purpose of this laboratory was to gain an understanding of the differences between the freezing points of pure solvent to that of a solvent in a solution with a nonvolatile solute, and to compare the two.

The next step in this lab is to rinse the Erlenmeyer flask with distilled water down the drain and then repeat the experiment, this time adding 10 ml of 0.10M KI and 10 ml of distilled water to the flask instead. The flask should again be swirling to allow the solution to succumb to the same temperature as the water bath and once it has reached the same temperature, 10 ml of 3% H2O2 must then be added and a stopper must be immediately placed on the flask and recording should then begin for experiment two. After recording the times, the Erlenmeyer flask must then be rinsed again with distilled water down the drain. After rinsing the flask, the last part of the lab can now be performed. Experiment three is performed the same way, but instead, 20 ml of 0.10 ml M KI and 5 ml of distilled water will be added and after the swirling of the flask, 5 ml of 3% H2O2 will be added. After the times have been recorded, data collection should now be complete.

Use ice if you need to. Then, fill one beaker with 175 mL of water and the other with 350 mL. Warm the water in the 350mL beaker up to 55 degrees celsius and cool the water in the 175mL beaker to 15 degrees celsius, the same temperature as the pitcher because it will be your control group. Once the beaker that should be heated is at 55 degrees celsius, pour 175 mL of the water into a glove and pour the other 175 mL into a ziplock baggie. Pour the 15 degrees celsius, 175 mL of water into another ziplock baggie. Before you set these in water, have a stopwatch ready and make sure that the water in the baggies and glove is at the right temperature.

Colligative properties, such as boiling point and freezing point, are dependent on the amount of solutes added, not necessarily their identities (LibreTexts, 2018). A fascinating concept related to freezing points is Supercooling. Supercooling is a state where liquids do not form ice even when they reach temperatures below their normal freezing point; they are trapped in a metastable state (Esrf.eu, 2018). The best example of this is clouds at high altitudes: they contain tiny droplets of water that do not have seed crystals, and therefore do not form ice despite the low temperatures (Esrf.eu, 2018). The concept of freezing point depression is applicable in many parts of everyday life.

When we can cool a liquid below its freezing point without it forming as a solid; this phenomenon, that still puzzles scientists today, is called supercooling. Supercooling keeps a liquid in the same state even when it is below its freezing point and when it should turn to a solid. Molecules are naturally sticky except while moving quickly when they bounce off each other. However, as the temperature drops, the molecules begin to stick together to form solids if it is cold enough. This happens as the temperature of a liquid drops and is helped by the presence of tiny particles, called crystal nuclei, which start the solidifying process. Supercooled liquid is unstable and will freeze in seconds on contact with tiny particles. The contact usually requires a force like a hit or a push of the liquid to make it

In class we examined all five liquids and identified the ones that froze. The five liquids were already in the freezer and froze by the time class started. Water and vinegar were frozen solid, while alcohol, and salty water

The control experiment for this investigation will be the experimental setup of 5 trials using 5oC as the temperature. All the steps in the method will be followed.

As stated, our solvent in this lab will be tert-butanol. We start by recording the freezing point of this substance without anything added. Then, we add various

Outline: Determine the missing properties and describe the phase of each mixture. There are 2 properties given for every single mixture, this is sufficient to calculate the other properties.