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Drawing Structures As Answers (Chem21Draw)

Drawing organic molecules is an essential part of GOB, Organic and Biochemistry courses. The Chem21Draw drawing canvas is embedded and integrated into the Chem21Labs homework and lab report webpages. The web-based drawing canvas is written in HTML5 and Javascript (JS) - the language that all broswer's read without a plugin. Chem21Draw is accessible from any operating system and on all devices. Its drawing and student feedback features are described below.

  1. Single Answer - students draw a single structure on the Chem21Draw drawing canvas and submit their answer.
    • Cyclohexene reacts with HBr, then Mg, followed by CO2 and H+ . . . . draw the final product.
    • Draw cis-1-tert-butyl-2-isobutylcyclobutane.
    • Draw the least stable alkene isomer of C6H12.
    • Draw a meso compound with the formula C8H18.
    • Draw the structure of the C2H3Cl3 isomer that shows a single absorption in the 1H NMR.

  2. Multiple Answers (unordered) - students draw multiple structures on the Chem21Draw drawing canvas and submit their answers.
    • Draw the two Intermediates of the following reaction . . . .

      Cyclopropanone + H+ / H2O → Cyclopropane-1,1-diol

    • Draw the four constitutional isomers for C2H5N.

    • Draw the three additional resonance structures for the cation to the right.

  3. Multiple Answers (ordered) - students draw the structure after each step in an Organic synthesis. The reagents can be placed above, below or to the side of the reaction arrow. The reaction arrow can be right, left, up or down . . . . resonance arrows can also be used.
    • Benzene reacts with the following reagents in the order shown.
      1. CH3Cl / AlCl3
      2. HNO3 / H2SO4
      3. Cl2 / FeCl3
      4. KMnO4 / H2O then H3O+

  4. Feedback - correct answers are overlayed with green circles . . . . incorrect answers have red circles. Specific feedback to guide students to the correct answer is displayed when mousing over a red circle. The circles and structures can be moved by dragging the move icon. Structures must be moved when they are "correct", but in the wrong spot - the structure is in green, but the circle overlay is red.

  5. Mechanism Arrows - students draw mechanism arrows to show flow of electrons in a chemical reaction. The mechanism arrows are drawn as Bezier curves that can be "shaped" to create the perfect curved arrow. Feedback is provided for incorrect answers - specifically the number of arrows expected and whether an incorrect arrow starts/ends at the correct atom.

To draw the structure below . . .

The structure one can draw following the directions. The structure has a cyclohexane ring, a methyl ether, a wedged methyl group and a dashed chlorine bond.
  1. Click on the Cyclohexane Ring icon and click/drag on the drawing palette until the desired orientation is obtained.
  2. Click on the Bond icon, click on the cyclohexane carbon and drag to the right - release the mouse button to complete the addition of a CH3 group. Repeat to add a CH3 group to the last carbon added. 
  3. Click on the Periodic Table icon and select Oxygen. Click on the last carbon added and drag/release to add the oxygen atom.
  4. Click on the Periodic Table icon and select Carbon. Click on the oxygen atom and drag/release to add the methyl group making a methyl ether.
  5. Click on the Wedged Bond icon, click the carbon atom connected to the cyclochexane ring and drag / drop to create a CH3 wedged bond.
  6. Click on the Periodic Table icon and select Chlorine. Click on the Dashed Bond icon. Click the carbon atom connected to the cyclohexane ring and drag/drop to create a dashed Cl bond.

Once a student has drawn the answer to the posed question, they would click the Submit button (not shown in this demo) to have their structure graded.