Calorimetry 1: The Enthalpy of Formation of MgO Overview Getting Started Techniques Procedure FAQ Full Lab Manual Introduction & Goals Chemistry & Background Key Questions Prelab Problems Safety Procedure In Your Write-up Experiments Index ChemLab Home		FAQ Index Question 1 Why are we using styrofoam cups, instead of more sophisticated equipment? Question 2 How does the Honor Principle apply to the labs with partners as far as calculating the change in T and uncertainty? I'm confused as to how the rule works. Question 3 How can I achieve the most accurate results for this experiment? Question 4 In prelab problem 3, what does heat of solution mean? How is it related to heat of dissolution? Submissions Submit a question or an answer to the FAQ Questions & Answers Question 1 Why are we using styrofoam cups, instead of more sophisticated equipment? Professor Milde Although a styrofoam cup may seem silly, it works very well. The insultation of styrofoam is effective at minimizing heat flow to the surroundings, thus making the calorimeter adiabatic. More sophisticated solution calorimeters are more fragile and more expensive and don't give results that are significantly better than styrofoam cups. Question 2 How does the Honor Principle apply to the labs with partners as far as calculating the change in T and uncertainty? I'm confused as to how the rule works. Professor Milde Partners can work together to figure out the change in T and do the data and uncertainty analysis, but both partners must do the calculating. So you can't divide the work and share the results, but you can work side-by-side and compare your results. The intent is to have everyone turn in work that is their own, not someone else's. Also not to take advantage of another's work for your own report. So if you work WITH your partner, in tandem, and turn in written work that consists of your own calculations, you have honored the honor principle. Question 3 How can I achieve the most accurate results for this experiment? Professor Milde There are several places where you should be careful, in order to obtain the most accurate results possible. Since you will determine the heat capacity of the calorimeter in one experiment and use it for the following experiments, it is vital that the calorimeter be the same for the three runs. In particular, the volume of solution should be identical. It is also important that all solution or solid be transferred to the calorimeter. Masses and volumes should be determined accurately and no material should be lost in transfer. Question 4 In prelab problem 3, what does heat of solution mean? How is it related to heat of dissolution? Professor Milde They are the same thing. It is the enthalpy change for the reaction (for example) NaCl (s) Na+ (aq) + Cl- (aq) Submissions Submit to the FAQ You can submit either a question or an answer to a question about this week's experiment. Your submission will be mailed to the site editor, who will respond to you directly and also add your submission to the FAQ page. Having trouble with the submission procedure? Check your Kerberos installation. If you lose the FAQ Submission window it may be hidden behind another browser window.
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