Students mouse over the 1H NMR spectrum to determine the chemical shifts of the various proton absorptions. A match of the wave numbers to the functional group absorbing at that frequency is best graded where the student selects the functional group's name from a drop-down (choice) menu. Students mouse over the IR spectrum to determine the wave numbers (cm -1) of the peaks indicated (1, 2, 3). Any of these masses can be reported in the lab report and automatically graded. Students mouse over the MS spectrum to determine the mass of the molecular ion, the mass of a fragmented ion, or the mass of the base peak. The λ max value is reported in the lab report and feedback is given when it is automatically graded. Students mouse over the UV spectrum of Carbaryl / 1-Naphthoxide to determine λ max (the x and y crosshair coordinates are shown on the right). Are the solubility results consistent with the structure of clove oil? Explain. The solubility of the isolated clove oil (from steam distillation) was determined in water, 5% NaOH and 5% NaHCO 3.Which peak in the 1H NMR will disappear on addition of D 2O? Explain.
The 1H NMR, 13C NMR, DEPT and HETCOR are used together to complete the final identification of clove oil.The 13C NMR reveals the number of aromatic / vinylic carbons and permits the elimination of more structures.The 1H NMR reveals the presence of aromatic and vinylic hydrogens and permits the elimination of more structures.The fact that clove oil has no plane of symmetry permits the elimination of more structures.IR gives information about the functional groups present and permits the elimination of some structures.For the rest of the lab, students use provided spectra to eliminate structures from this list. From the formula and degrees unsaturation, 20 possible structures (right) of clove oil are given to the students.Next, the degrees unstaturation are calculated from the molecular formula.These two pieces of information provide the molecular formula. Each instrument gives the students a "piece of the puzzle". Chem21Labs has developed an Organic lab where students work in groups of four to isolate Clove Oil (Steam Distillation) and in the same groups they complete a Clove Oil "dry lab" where they must answer questions using the MS, IR, 1H NMR, 13C NMR | DEPT and HETCOR spectra. drag / read a ruler) is present in some spectra.Īll the spectra except the UV are of Eugenol ( Clove Oil). All spectra have a cursor that displays the abscissa value. Shown below are six sample interactive spectra: UV, MS, IR, 1H NMR, 13C NMR | DEPT and HETCOR. Heat Capacity of a Styrofoam Calorimeter.Automatic Grading of Accuracy and Precision of Lab Results.Automatic Grading of Reported Significant Figures of Lab Calculations.Automatic Grading of Reported Precision of Lab Data (Decimal Places).About Chem21Labs | Home | Contact Us | Reference Material