Freezing Point Depression Lab

In order to fulfil the labs purpose, the lab was split into two parts. The first part consisted of measuring and determining the freezing point depression of the solution water. The second part consisted of measuring and determining the freezing point depression of a solution that consisted of water and an unknown solute.

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.

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.

The melting point of the final product, diphenylacetylene, was found to be 65-68 degrees Celsius which is right around the ideal 61 degrees Celsius melting point; this shows that purification during the lab worked and that the sample was almost 100% pure. Since only 0.01g of diphenylacetylene was collected and the theoretical yield was calculated to be 0.049g, this experiment had a 20.41% yield. A few sources of error that explain the low percentage could be the loss of crystals when transferred from the test tube to the suction apparatus or when they were transferred from the suction apparatus to the filter paper to be dried and then weighed. Crystals could have also been lost if more than 5 drops of methanol was added because excess methanol would dissolve the crystals. The experiment was successful when looking at the crystals collected from the addition step and the elimination step; however, to improve the percent yield and collected product the the test tubes could have been allowed to cool down in the ice bath past the 5 minutes to ensure all the crystals formed

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.

The objectives in this laboratory were to be able to calculate the freezing point depression among three trials of unknowns, be able to correctly measure the freezing points of p-xylene, and to be able to calculate the molar masses of the unknowns by found freezing point depression values. This was done to be able to understand and apply a concept names supercooling. Supercooling is when a liquid is put far under its original freezing point and remains a liquid or gas. This happens when a substance is cooled so quickly that it’s easier for it to stay a liquid than to crystalize, until it reached its nucleation point and begins to heat up returning to its freezing point (image 4). The supercooling of p-xylene was observed in three

Introduction: The experiment's goal was to determine the freezing point of a pure solvent and the freezing point depressions of two solutions. The freezing point and the freezing point depressions were determined by graphing the temperature of the pure solvent and two solutions as they cooled and observing when crystals first formed.

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.

Densities, for three binary mixtures- Cyclohexane (CHXN) + Toluene (TN), + o-Xylene (OXN) and + Mesitylene (MSTN) were measured at T = (303.15, 308.15, 313.15, 318.15 and 323.15) K. The measurements were carried out over the whole range of composition, using a 10 cm3 bi-capillary pycnometer. The excess molar volumes, VmE, apparent molal volumes, v, thermal expansivities, , and excess thermal expansivity, , were calculated from the density data. The VmE results were correlated with the fourth-order Redlich-Kister equation. Variations in the calculated excess properties for the liquid mixtures were studied in terms of intermolecular interactions. It was found that the values of VmE are dependent on temperature and in all cases increases

The salt lowers the temperature at which water freezes and melts. Pure water, H20, freezes as it melts at, 0°C (32°F). But when salt is increasing, the freezing point is dropped. Salt and water, as different substances, they both carry different chemical properties. Salt gets in the way of the interactions between H and O, making it hard for H and O to bond as ice.

Introduction Molar mass is a fundamental quantity of chemistry. There are multiple ways to find the molar mass of a substance experimentally; one way is to use Freezing Point Depression by using the following equation: ΔT= kf*m (Robinson, 2018). The purpose of this lab was to do just that; measure the freezing point depression of a solution when a solute is added to a solvent, and from that, determine the molar mass of an unknown substance, along with learning about the influence that solutes have on liquid properties. A concept of importance to this experiment is freezing point. According to LibreTexts, “Freezing point depression is a colligative property observed in solutions that results from the introduction of solute molecules to a solvent…and

The objectives of this lab are, as follows; to understand what occurs at the molecular level when a substance melts; to understand the primary purpose of melting point data; to demonstrate the technique for obtaining the melting point of an organic substance; and to explain the effect of impurities on the melting point of a substance. Through the experimentation of three substances, tetracosane, 1-tetradecanol and a mixture of the two, observations can be made in reference to melting point concerning polarity, molecular weight and purity of the substance. When comparing the two substances, it is evident that heavy molecule weight of tetracosane allowed

Freezing point depression is a colligative property observed in solutions that results from the introduction of solute molecules to a solvent. The freezing points of solutions are all lower than that of the pure solvent and are directly proportional to the molality of the solute.

To apply thermal analysis to the two-component system, naphthalene-biphenyl at atmospheric temperature. The analysis will be represented by a solid-liquid phase diagram (freezing point diagram).

The purpose of this lab was to study colligative properties. These properties are properties that are affected when a solute is added to a solvent. Thus, the amount is important, not the actual type of substance, for the colligative properties. A couple types of this property are the freezing point and boiling point of a substance. (1)