To determine the molar mass of the solute the freezing point depression t = kf where kf is the molal freezing point 12_freezing point depression_w10. Molecular mass by freezing point depression prelab purpose graphs conclusion 1 to determine the molecular mass of an unknown substance by finding the freezing point of two solutions (bht and para-dichlorobenzene, and bht and the unknown group 1 trial 1 the molecular mass of the unknown substance is 307 g/mol. Lab 7 - determination of the molar mass of an unknown solid by freezing point depression goal and overview in the first part of the lab, a series of solutions will be made in order to determine the freezing point depression constant, k. The freezing point depression can be we will investigate the phenomenon of freezing point depression and determine the molar mass the freezing point. Experiment: molar mass by freezing point depression objectives • the molar mass of an unknown compound will be determined using freezing point depression. How can the answer be improved. The freezing point of a solution that contains 100 g of an unknown compound, (a), dissolved in 100 g of benzene is found to be 207 oc the freezing point of pure benzene is 548 oc the molal freezing point depression constant of benzene is 512 oc/molal.
Answer to molecular mass by freezing point depression show your work please procedures: experiment 1: measure the freezing point. Ap chemistry lab #7 page 1 of 3 lab #7: determining molar mass by freezing point depression background information: chemistry is the study of the chemical and physical properties of substances. Molar mass from freezing point depression introduction: when a pure substance freezes, the individual particles (molecules, atoms, ions) must organize themselves. Where dt is the freezing point depression, kf is the freezing point depression constant for a particular solvent (39°c•kg/mol for lauric acid in this experiment) and m is the molality of the solution (in mol solute/kg solvent.
Calculate the molar mass of the solute calculating the molar mass of a solute from freezing point you know the freezing point depression of the solution. The freezing point of a solution that contains 100 g of an unknown compound, (a), dissolved in 100 g of benzene is found to be 207 oc the freezing point of. Experiment#4molarmassbyfreezingpointdepression calledfreezingpointdepressionandisacolligativepropertyofsolutionscolligativepropertiesdepend.
Molar mass by freezing point depression ntroduction a procedure for determining the molar mass of a substance is very useful to chemists the molar mass is in important value that must be known in order to identify an unknown substance or. The phenomenon of freezing point depression has many the molar mass of a solute is determined by comparing m t f is the normal freezing point of the. Webpage- this short video shows you how to calculate the molar mass of a.
Experiment molar mass by freezing point depression objectives: in this experiment, you will determine the freezing point of cyclohexane and the freezing point. Return to the freezing point depression discussion return to solutions menu problem #11: when 200 grams of an unknown nonelectrolyte compound are dissolved in 5000 grams of benzene, the freezing point of the resulting solution is 377 °c.
Molecular mass by freezing point depression procedure part i: freezing point of pure water 1 obtain a clean, dry test tube or vial determine the mass of the test tube or vial place about 10 ml of distilled water in the test tube or vial, and reweigh determine the mass of the water used record the mass of the water in the data table 2.
Determination of molecular mass by freezing point depression page 2 of 10 in this experiment we shall use the freezing point depression of a solvent to determine the molecular mass of the unknown solute. Colligative properties: freezing-point depression and molar mass lab report. I use cetyl alcohol to calculate freezing point depression constant my data from the experiment freezing point of pure bht: 670 degrees celsius freezing point of bht+cetyl alcohol: 597 degrees show more i'm trying to determine the molar mass of an unknown substance by using freezing point bht is my solvent. In chemistry, the molar mass m is a physical property defined as the mass of a given substance divided by the amount of substance the base si unit for molar mass is kg/mol however, for historical reasons, molar masses are almost always expressed in g/mol as an example, the molar mass of water: m. The goal is to find the freezing point depressions of various antifreeze solutions, and use this information to find its molar mass. Lab # 13 – molecular weight determination by freezing point depression revised 8/19/2009 3 to find the intersection of the two lines, solve the two equations, 4 and 5, simultaneously for y. Molar mass by freezing point depression introduction when a nonvolatile solute is dissolved in a solvent, the freezing point of the solution is lowered.