# Determining Molar Mass by Freezing Point Depression

556 Words3 Pages
Lab 1: Determining Molar Mass by Freezing Point Depression Xiaoyu Shi Partha P Samadder CHEM 152IN(CRN:12570) September 14, 2014 * Introduction: In this experiment, we are going to measure the freezing point depression of an aqueous solution of an unknown organic compound. Determine the molar mass of the unknown compound from the freezing point depression data. We also will practice the formula applied to freezing point depression, the molality and the molarity. We will use ice-salt water and a thermometer to determine the freezing point of the unknown organic compound. Then we can use the formula to find the molar mass of the unknown organic compound. So that we will be able to presume what kind of organic compound the sample is. * Procedures outline: Sample type: Sample B * Methods: 1. We will use the ice-salt water bath to cool down the solution of sample B, because salt water can help it to be easier to get target temperature -7°C to -10°C. And it is also easier for the ice-salt water bath to main that temperature for longer time. 2. When using the test tube and electronic scale to weight the mass of the test tube, the test tube and the sample compound solute, the test tube, the sample compound solution. We will need to clean up the scale first before we weigh them. When weighing the test tube and the sample compound solution. We will need to put a beaker to make the test tube fixed on the scale. But we need to zero the scale after putting the beaker on the beaker. * Materials: 1. A large amount of ice 2. Salt 3. Distilled water 4. Sample unknown compound B * Equipment: 1. Beakers, (both large and small) 2. Test tubes, 3. Thermometer, 4. Glass stirring rob 5. Electronic weigh scale * Result: * Data sheet 1 (Measuring the freezing point of distilled water) 1. First trial