Freezing Point Depression Lab Report

Other substances that dissolve in water also lower the freezing point of the solution. The amount by which the freezing point is lowered depends only on the number of molecules dissolved, not on their chemical nature. This is an example of a colligative property. In this project, you'll investigate different substances to see how they affect the rate at which ice cubes melt. You'll test substances that dissolve in water (i.e., soluble substances), like salt and sugar, as well as substances that don't dissolve in water (i.e., insoluble substances), like sand and pepper. Which substances will speed up the melting of the ice?

An instant cold pack is a device which is composed of 2 sacks, one which contains water, and the other with another chemical. When the user wishes to activate the cold pack, she squeezes it, and breaks the boundary between the water and the chemical. This causes an endothermic reaction as the water dissolves the chemical. The reaction then lowers the pack’s temperature by absorbing heat from the surroundings. Cold packs typically utilize the chemicals ammonium nitrate, calcium ammonium nitrate, or urea. A cold pack using ammonium nitrate will typically hit a low of 1.67℃ for 10 to 15 minutes. However, for the purposes of the first portion of the experiment, the chemicals being tested were ammonium chloride, sodium chloride, and calcium

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 this lab, the molar mass of a volatile liquid is determined based on its physical properties in the vapor state. In order to calculate the molar mass, the mass, temperature, pressure, and volume is measured independently and then converted to the correct units. Sample C was obtained at the beginning of the experiment, which was later informed to be ethanol. Based on the calculations made, the molar mass of the volatile liquid was 95.9 g/mol. However, compared to the known value of 46.1 g of ethanol, the value measured had a 108% error. Unfortunately, this was a very big percent error and may have been caused by incorrectly measuring the volume of the gas. Using the ideal gas law, the molar mass of a volatile compound was calculated in order

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

First, students find the average temperature of the solvent by averaging the two temperatures found with the test tube with only the t-butyl alcohol. Students then find the freezing point of the t-butyl alcohol and the unknown mixture through using an equation that goes Temp =(m2b1-m1b2)/(m2-m1). From our lab group experiment, the average temperature of the pure t-butyl alcohol was 23.1 degrees Celsius and the mixture was 12.0 degrees Celsius. After finding the two temperatures, we subtracted the average temperature of the t-butyl alcohol and the freezing point of solution to get 11.1 degrees Celsius. Then, we divided the 11.1 by 8.37 °C/m to get the molality, which was 1.32616 m. Afterwards, we found the moles of solute by multiplying the kilograms of the t-butyl alcohol (0.01898 kg) by the molality to get 0.025170 moles. To find the molar mass, you divide the mass of the unknown by the moles of the unknown. When our group did these steps, we got an answer of 125.5 g/mol as our final

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.

Introduction The purpose of this lab was to explore the colligative properties, in this case freezing point and freezing point depression, of the solvent p-xylene. The freezing point of p-xylene was obtained using the MicroLab program and a thermistor temperature sensor. From this data, the freezing point depression constant, kf, could be found, as well as identifying three unknown solutes by calculating their molar masses.

The purpose of this experiment is to identify an unknown substance by measuring the density and boiling point. I will be able to conclude which substance is my own from a list of known options stating what its real boiling point and density is.

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 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)

In order for water or milk to freeze, the temperature needs to be at or below 0ºC. In order to lower the freezing point of solution, different solutes can be added. A solution is created by dissolving a solute into a solvent, such as dissolving sugar (solute) into water (solvent). The process of decreasing a freezing point of a liquid by dissolving a solute into a solution is referred to as freezing point depression. The freezing point is a colligative property, which means that the freezing point depends on the number of solute particles dissolved in a solution. For example, CaCl2, which has three particles, would lower the freezing point of a solution more than NaCl would, which only has two particles (Helmenstine).

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.

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

To achieve this, the final value from each thermocouple was set to be equal to the warm water bath temperature (370C), and the initial reading was set equal to the ice water bath temperature. Thus, for each thermocouple an equation was obtained using the two points to convert voltage readings to temperature. An example of the calibration for one of the thermocouples is shown in Appendix II.