Freezing Point Depression Lab

To make the results of the experiment valid four variables to take into account are if the freezer is the same temperature for both tests, the water is the same water just different temperatures, the ice cube trays are the same size, and finally both trays are in the freezer for the same amount of time.

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

If the temperature in the apparatus increases too quickly, it’s difficult to record to exact temperature at which the first drop of liquid falls and then again when the mixture is completely liquid. This would result in the wrong melting point range being recorded. Additionally, experiment three heavily relied on the results from experiment two. Failing to extract all the aspirin from the organic solution in experiment two would result in more impurities in the unknown component. Thus, lowering and broadening the melting point

Procedure: Using distilled water, premeasured containers and objects determine displacement of fluids and density of objects. Use ice and heat measure temperatures in Celsius, Fahrenheit and Kelvin.

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.

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 purpose of this experiment is to measure the reaction of the ice melting when exposed to another solid element. The environment is a kitchen with a stable temperature and testing space. Repeating the tests three times will provide different data which will then be averaged for each element. For each test, calculate the percentage of the ice cube melted by [mass of melt water/initial mass of ice cube] x 100.

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.

In the third stage of this experiment, the density of a liquid was determined and compared to known standards. A 100ml beaker was filled to about half-full with room-temperature distilled water. The temperature of the water in ◦C was recorded in order to compare to known standards later. A 50ml beaker was then weighed on a scale in order to determine mass and recorded. A sample of the distilled water with an exact volume of 10ml was then placed in the 50ml beaker using a volumetric pipette. The 50ml beaker with the 10ml of water was then weighed again and the initial mass of the beaker was subtracted from this mass to obtain the mass of the 10ml of water. With the volume and the mass of the water now known, density was calculated using d = m/V and recorded in g/ml. This process was then repeated to check for precision and compared to standard values to check for accuracy. Standard values were obtained from CRC Handbook, 88th Ed.

With time (t) on the x-axis and temperature (Celsius) on the y-axis, the exponential change could be easily observed. At the beginning of the laboratory the masses of the combined polypropylene test tube and 100 mL beaker were recorded by a digital electronic scale. A dry polypropylene test tube was obtained and approximately 2 mL of p-xylene was squirted into it with the use of a pipette. This was added to the beaker and weighed. 10 drops of toluene was then added and weighed again. The polypropylene test tube, which now contained 10 mL of p-xylene and 10 drops toluene was removed from the beaker and placed into a replica 100 mL beaker which was halfway filled with an ice water mixture. The temperature sensor, which was connected to the microlab application was placed inside of the polypropylene test tube and stirred rapidly around the outskirts of the bottom of the polypropylene test tube. The mixture began freezing, giving off an icy slush complex. Once the temperature appeared to have reached the nucleation point and leveled out at its freezing point, the application was stopped. This value was recorded in the laboratory manual. The temperature sensor was rinsed off then wiped, the beaker was re-filled with ice, and the test tube was put into the test tube rack to be thawed. Once thawed, this was discarded into the waste bin

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.

4. Remelt the contents of the tube and add the counterpart component based on the given schedule. Ask the demonstrator to adjust the cooling water between mixtures. During the experiment, record and plot the data obtained for all mixtures listed. The experiments are stopped as follows:

The topic is Chemistry of Making Ice-Cream: Lowering the Freezing Point of Water. In this experiment the scientist will be researching how to lower the freezing point of water using salt and/or sugar. The Independent Variable in this experiment is the solutes that the scientist uses which are, chemicals that dissolve in liquids. The Dependent Variable is the temperature/freezing points of the substances(°C). A constant is this experiment would be the use of salt and sugar and the control would be the pure water because it is important for determining the freezing point of the water in the experiment.

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

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