2. A molecule with no polar bonds is nonpolar.

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Presentation transcript:

2. A molecule with no polar bonds is nonpolar. QUESTION: Which of the following is/are true? 1. A nonpolar molecule can have polar bonds. 2. A molecule with no polar bonds is nonpolar. A. 1 only, B. 2 only, C. both, D. neither Statement 1 is True. If polar bonds are symmetricially oriented, the molecule would be nonpolar. Statement 2 is True. A molecule must have at least one polar bond in order to be polar. Which of the following is/are true? 1. A nonpolar molecule can have polar bonds. 2. A molecule with no polar bonds is nonpolar. A. 1 only, B. 2 only, C. both, D. neither PAUSE CLICK Statement 1 is True. If polar bonds are symmetricially oriented, the molecule would be nonpolar. click Statement 2 is True. A molecule must have at least one polar bond in order to be polar. There’s no way for a molecule to be polar if it doesn’t have any polar bonds. Therefore, the correct answer is C. Both statements are true. CLICK CONTINUED ON NEXT SLIDE

Examples of nonpolar molecules with symmetrically-oriented polar bonds: CO2 and CF4 Here are examples of a nonpolar molecules that has polar bonds. In Carbon dioxide, the Carbon-to-Oxygen bonds are polar, since oxygen is much more electronegative than carbon. But the two carbon-to-oxygen bonds are oriented in opposite directions. CLICK CLICK So, the molecule overall is nonpolar. In carbon tetrafluoride, the carbon-to-fluorine bonds are polar, since fluorine is more electronegative than carbon. But the four carbon-to-fluorine bonds are oriented in symmetrically. CLICK CLICK CLICK CLICK PAUSE CLICK PAUSE END RECORDING

Video ID: 3-12-1 © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Glenn V. Lo Narrator: Funded by Louisiana Board of Regents Contract No. LA-DL-SELECT-13-07/08