freezing point depression experiment error Shipshewana Indiana

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freezing point depression experiment error Shipshewana, Indiana

As well, by not stirring enough to prevent supercooling, the freezing point could have been affected. If you spill any sulfur, make sure you clean it up. The colligative-property law describes these effects, stating that the "freezing point and boiling point of a solution differ from those of the pure solvent by amounts that are directly proportional to Human error is the largest error.

It's fast and easy... There are 12.1 moles of HCl per liter of solution. Menu Log in or Sign up Contact Us Help About Top Terms and Rules Privacy Policy © 2001-2016 Physics Forums Colligative Properties: Freezing-Point Depression and Molar Mass Let's become familiar with Fill the 600 mL nearly full of water and heat till the water temperature is about 85 C.

The freezing point is lowered by the solutes in the solution as detailed above. Techniques to prevent supercooling were practiced. Carefully add the sulfur to the test tube. For major sources of error in this experiment, consult the second paragraph of the Discussion section. 2.

In a .050 m solution of NaCl in .150 kg of water, the mass of NaCl is as follows: (view) .050 m = X moles NaCl ÷ .150 kg water × When the naphthalene has solidified, throw both the paper and solid into the designated waste receptacle. Observations: ► A. This would indicate a smaller molality of benzoic acid thanthe actual value of the molality of benzoic acid of the solution.

The temperature reading from the thermometer was recorded every 30 seconds. The solvent boils when the vapor pressure, or tendency of solvent molecules to escape, is equivalent to the atmospheric pressure. A volatile substance ha a high vapor pressure and a nonvolatile substance has a low vapor pressure at room temperature. Your cache administrator is webmaster.

Insert the test tube into the beaker. When the temperature remained constant for several readings, the naphthalene was allowed to cool without further temperature readings. ► B. Everyone who loves science is here! Create a free website Powered by Create your own free website Start your own free website A surprisingly easy drag & drop site creator.

When molecular mass is calculated based on this, the calculated value for the molecular mass of benzoic acid would increase, because the number of grams present is being divided by asmaller number The stopper was removed and the sulfur was poured in. The phase diagram below illustrates the effect of adding a solute to a pure substance: (view | download) As demonstrated by the phase diagram above, adding a solute to a solvent Remove the stopper and remove the molten naphthalene onto a crumpled wad of paper.

The freezing temperature is difficult to ascertain by direct visual observation because of a phenomenon called supercooling and also because solidification of solutions usually occurs over a broad temperature range. Yes, Please make this my home page! Place the stopper in the test tube. Discussion of theory The major scientific concept covered by this lab was freezing point depression.

If the freezing point of the solution had been incorrectly read 0.3 lower than the true freezing point, would the calculated molar mass of the solute be too high or too From this lab we can also conclude that the molecular mass of antifreeze isapproximately 62.5g/mol. The stopper was replaced and the solution was stirred gently until all of the sulfur had dissolved in the naphthalene. Mole of Benzene: (6.50 g)(78 g/mol) = .083 mol (.083 mol)/(.160 kg) = .520 molal D T = (4.68C/m)(.520 molal) = 2.43C -63.5C - 2.43C = 61.07C = 61.1C

The thermometer was not allowed to touch the bottom or sides of the test tube. Pre-Lab Discussion Distinguish between solute and solvent. Since the solution is 37.2% HCl: 1190 g × (.372) = 442.68 g HCl per 1190 g solution. First, the freezing point of the pure solvent had to be determined and so if some of the solvent was on the walls of the test tube opposed to in the

The freezing point of naphthalene will be determined experimentally; then a controlled solution of naphthalene and sulfur will be made, and the freezing point of that solution will be determined. The molality is therefore 12.1 ÷ .74732 = 16.2 m. It would have helped if you had included these details in the opening post. Are you sure you want to continue?CANCELOKWe've moved you to where you read on your other device.Get the full title to continueGet the full title to continue reading from where you

The atomic theory of matter offers explanations for bonding and physical phase. Please try the request again. Unfortunately these cooling curves are not available online. The molar mass would not be affected because the change in temperature would always be the same.

NH3(aq). 1 L solution (.90 g/mL) = 900 g of solution per liter. Using a timepiece and the thermometer measure the room temperature every 30 seconds and record it in Data Table A under "Cooling-Curve data". In order to determine the molar mass of 2.00 g of para-dichlorobenzene in 50.0 g of cyclohexane using colligative equations, the following equations must be employed: (view) ΔTf = Kf×m 5.55°C SchellChemistry - A Molar Mass From Freezing Point Depressionby Chánh Hiếu07 - Determining Molar Mass by Freezing Point Depressionby Stephanie RobertshawPOSTLAB Experiment No.3by Jho YusonFreezing Point Depressionby Josh TingleyMolar Mass by

Chemistry: The central science: laboratory experiments, eighth edition. It was heated to about 85°C. Record the temperature until you have reached the freezing point, or when crystals start to form. Sources of error One source of error for this lab is unwanted contaminants in the H2O used since the H2O was taken from the tap instead of using distilled water.

Yes, my password is: Forgot your password? When the vapor pressure of a solvent is equal to atmospheric pressure, the solvent boils. When this mixture was added to the H2O it caused thefreezingpoint of the H2O to change from 0C to -3C a freezing point depression of -3C. Imperfect reading of thethermometerwould cause a error in the freezing point depression calculations.

The colligative properties include vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure. Obviously, volatility is a relative term and depends upon temperature and pressure. No, create an account now. Log in with Facebook Log in with Twitter Your name or email address: Do you already have an account?