Question

activity c (continued from previous page)

1. experiment: drag two o₂ molecules into the simulation area, but do not click play yet

a. what force do you expect to see between o₂ molecules?
b. click play and observe. what do you notice?
c. which force causes attraction between o₂ molecules?

1. experiment: drag an o₂ molecule and an h₂o molecule into the simulation area. click play, and then click pause when you see a bond form.

a. what happens to the end of the o₂ molecule that is closest to the positive end of the h₂o molecule?
b. as the bond forms, does the polarity of the o₂ molecule change?
c. classify this combination of molecules. (it might take a few tries to get it right.) which type of intermolecular force is acting here?
when a polar molecule approaches a nonpolar molecule, the electron cloud of the nonpolar molecule may become distorted, causing the nonpolar molecule to become temporarily polar. for example, if the negative end of the polar molecule approaches the nonpolar molecule, the electron cloud of the nonpolar molecule will be repelled, causing a slight positive charge at that end of the nonpolar molecule. the resulting attractive force is called a dipole - induced dipole force.

1. classify: drag out different combinations of molecules in the gizmo and categorize them. give at least three examples of molecule combinations for each intermolecular force.

dipole - dipole forces dipole - induced dipole forces london dispersion forces

1. summarize: fill in the blanks to summarize the patterns you see.

____________________ forces arise between polar molecules.
____________________ forces arise between nonpolar molecules.
____________________ forces arise between polar and nonpolar molecules.

Explanation:

Step1: Analyze O₂ - O₂ interaction

O₂ is a non - polar molecule. Non - polar molecules have London dispersion forces between them. So for 4A, the expected force is London dispersion force.

Step2: Observe O₂ - O₂ in simulation

When clicked play, one would notice random fluctuations in the electron cloud leading to temporary dipoles and weak attractions, which are characteristics of London dispersion forces. For 4B, molecules show weak, random attractions.

Step3: Identify O₂ - O₂ attractive force

The force causing attraction between O₂ molecules is London dispersion force as non - polar molecules interact via this force. So for 4C, the answer is London dispersion force.

Step4: Analyze O₂ - H₂O interaction

The end of the O₂ molecule closest to the positive end of the H₂O molecule will have its electron cloud distorted. For 5A, the electron cloud of the O₂ molecule gets distorted.

Step5: Check O₂ polarity during bond formation

The polarity of the O₂ molecule does not change as it is a non - polar molecule and the distortion is temporary. So for 5B, the answer is no.

Step6: Classify O₂ - H₂O intermolecular force

This is a dipole - induced dipole force as H₂O is polar (dipole) and O₂ is non - polar and gets an induced dipole. For 5C, the intermolecular force is dipole - induced dipole force.

Step7: Provide examples of intermolecular forces

For dipole - dipole forces: H₂O - H₂O, NH₃ - NH₃, HF - HF. For dipole - induced dipole forces: H₂O - O₂, HCl - N₂, CH₃OH - CO₂. For London dispersion forces: N₂ - N₂, O₂ - O₂, F₂ - F₂.

Step8: Summarize intermolecular force patterns

Dipole - dipole forces arise between polar molecules. London dispersion forces arise between non - polar molecules. Dipole - induced dipole forces arise between polar and non - polar molecules.

Answer:

4A. London dispersion force
4B. Molecules show weak, random attractions
4C. London dispersion force
5A. The electron cloud of the O₂ molecule gets distorted
5B. No
5C. Dipole - induced dipole force

1. Dipole - dipole forces: H₂O - H₂O, NH₃ - NH₃, HF - HF; Dipole - induced dipole forces: H₂O - O₂, HCl - N₂, CH₃OH - CO₂; London dispersion forces: N₂ - N₂, O₂ - O₂, F₂ - F₂
2. Dipole - dipole; London dispersion; Dipole - induced dipole