5.3 Study Guide Flashcards
Describe the intermolecular attraction of London dispersion.
The London Dispersion Forces attraction is a temporary attraction to other atoms/molecules. It is caused by the movement of electrons in a molecule. This is the weakest attraction out of the three intermolecular attractions.
Describe the intermolecular attraction of dipole-dipole.
A dipole-dipole attraction takes place when two polar covalent molecules are attracted to each other. The partial negatively charged side of one molecule is attracted to the partial positively charged side of the other molecule. An example of a dipole-dipole interaction is a hydrogen bond. This is the second strongest attraction out of the three intermolecular attractions.
Describe the intermolecular attraction of Hydrogen bonds.
Hydrogen bonds occur when a hydrogen atom in one molecule is attracted to another atom in another molecule. an example of this is with hydrogen and oxygen. The two atoms are attracted to one another, forming a polar covalent bond. Hydrogen can also bond with nitrogen, fluorine, and other atoms. This is the strongest of the three intermolecular bonds.
Rank the intermolecular attractions from weakest to strongest and vice versa in solution.
Weakest 1-Strongest 3
- London dispersion, it is a temporary attraction caused by the electrons moving in the molecule
- Dipole-Dipole, it is a bond between the positively and negatively charged atoms of two polar covalent molecules.
- Hydrogen Bonds, a stronger version of a dipole-dipole bond. It forms when a hydrogen atom forms a polar covalent bond with another atom.
A molecule has a nitrogen atom in the middle that forms bonds with three different hydrogen atoms around it. The molecular dipole is pointing up and away from the hydrogen molecules. Is this molecule polar or nonpolar?
This molecule is polar because the hydrogen atoms have a lower EN than the nitrogen atom. The nitrogen atom is pulling on the electrons from the hydrogen atoms, causing it to have a partially negative charge. This gives the hydrogen atoms a partially positive charge. This results in an uneven dispersion of electrons, which causes an imbalance, making this a polar molecule.
A molecule contains one oxygen atom and two hydrogen atoms. The oxygen atom is pulling on the other two atoms, creating a polar covalent bond with both hydrogen atoms. What type of intermolecular attraction will this molecule be able to form?
The molecule will be able to form LDF, Hydrogen bonding, and dipole-dipole attractions. Every molecule can form an LDF attraction. The molecule can form a dipole-dipole attraction because there is a polar covalent bond between the oxygen and hydrogen atoms, and hydrogen atoms are present, which means that hydrogen bonding can occur as well.
A methane atom contains one carbon atom and four hydrogen atoms. The pulling forces of the hydrogen atoms cancel each other out, so the molecule is nonpolar. Would this molecule be soluble in water?
No, this molecule would not be soluble in water because it does not contain any OH bonds. The methane molecule does not have these bonds, and therefore cannot bond with the water molecule.
