Molecule Polarity Simulation

Molecule Polarity Simulation Visit the Molecule Polarity simulator. 1. Select the “Real Molecules” simulation option (click on the “Real Molecules Only in Java” link; you will then be prompted to download the simulation). Once you download the simulation to your device, open the simulation and begin the activity. Set 1: HF vs. H2 For each molecule be sure to have the “Atom Labels” and “Atom Electronegativies” button selected. Use the “Bond Dipoles” and “Molecular Dipoles” buttons to determine if these dipoles are present when instructed below. (a) Use the simulation to determine if bond dipoles are present on each molecule. (b) Use the simulation to determine if a molecular dipole is present on each molecule. (c) Use the simulation “Electrostatic Potential” option to map the electron density on each molecule. Molecule Electronegativity Bond Dipoles Difference Present? between atoms (yes or no) H2 2.1 – 2.1 = 0 no Molecular Dipole Present? (yes or no) no HF yes 4.0 – 2.1 = 1.9 yes Sketch/describe the Electrostatic Potential Question 1: Using what you learned from Set 1, predict what properties of the molecule determine if a molecular dipole is present or not. Molecules with non-polar bonds will be non-polar. Molecules with polar bonds might be polar. Set 2: Repeat the data collection carried out in Set 1 for each set molecules below. Be sure to have the “Atom Labels” “Atom Electronegativies” button selected. Use the “Bond Dipoles” and “Molecular Dipoles” buttons to determine if these dipoles are present when instructed below. (a) Use the simulation to determine if bond dipoles are present on each molecule. (b) Use the simulation to determine if a molecular dipole is present on each molecule. (c) Use the simulation “Electrostatic Potential” option to map the electron density on each molecule. Molecul e BF3 Electronegativity Difference between atoms 4.0 – 2.0 = 2.0 Bond Dipoles Present? (yes or no) yes Molecular Dipole Present? (yes or no) no NH3 3.0 – 2.1 = 0.9 yes yes Molecul e H2O Electronegativity Difference between atoms 3.5 – 2.1 = 1.4 Bond Dipoles Present? (yes or no) yes Molecular Dipole Present? (yes or no) yes CO2 3.5 – 2.5 = 1.0 yes no Molecul e Electronegativity Difference between atoms 2.5 – 2.1 – 0.4 Bond Dipoles Present? (yes or no) Yes (small) Molecular Dipole Present? (yes or no) no CH4 Sketch/describe the Electrostatic Potential Sketch/describe the Electrostatic Potential Sketch/describe the Electrostatic Potential CH3F C-H 2.5 – 2.1 = 0.4 C-F 4.0 – 2.5 = 1.5 yes yes Molecul e H2O Electronegativity Difference between atoms 3.5 – 2.1 = 1.4 Bond Dipoles Present? (yes or no) yes Molecular Dipole Present? (yes or no) yes NH3 3.0 – 2.1 = 0.9 yes yes Molecul e Electronegativity Bond Dipoles Molecular Difference Present? Dipole Present? between atoms (yes or no) (yes or no) C-H 2.5 – 2.1 = yes yes 0.4 C-F 4.0 – 2.5 = 1.5 CH3F CHF3 C-H 2.5 – 2.1 = 0.4 C-F 4.0 – 2.5 = 1.5 Analyze and Evaluate: yes yes Sketch/describe the Electrostatic Potential Sketch/describe the Electrostatic Potential (a) Compare the molecules that have a net molecular dipole and those that do not. What are the common features for the molecules that have net molecular dipoles? Molecules with net dipoles have polar bonds and asymmetrical shapes. (b) Compare the molecules that have a net molecular dipole and those that do not. What are the common features for the molecules that DO NOT have net molecular dipoles? Molecules with no net dipoles either have non-polar bonds, or have polar bonds and symmetrical shapes. (c) Create a general statement that summarizes how you can predict if a molecule will polar or not (i.e., create a statement that begins “A molecule will have a net molecular dipole if…”). A molecule will have a net molecular dipole if it has polar bonds and a VSEPR shape that is asymmetrical.