Here are a few answers to questions you may have:
1. Nitrogen comprises 78% of the atmosphere while Oxygen comprises 21%. These two gases have low boiling points therefore can exist as gases under normal environmental conditions. How can the intermolecular forces that exist between the Nitrogen molecules or the Oxygen molecules explain the low boiling points?
1. Nitrogen gas (N2) and oxygen gas (O2) are non polar molecules, therefore the intermolecular force that exist between two molecules of each is dispersion force which is the weakest intermolecular force. So they have low boiling points since they are easily broken apart.
1. Nitrogen gas (N2) and oxygen gas (O2) are non polar molecules, therefore the intermolecular force that exist between two molecules of each is dispersion force which is the weakest intermolecular force. So they have low boiling points since they are easily broken apart.
2. The Hydrogen Sulfide molecule (H2S) and the water molecule (H2O) are very similar. However, the boiling point of Hydrogen Sulfide is -60˚C whereas the boiling point of water is 100˚C. How can the intermolecular forces explain this difference?
2. H2O and H2S are both polar molecules therefore 2H2O bonded together and 2H2S bonded together have dipole-dipole force between them. Yet the dipole-dipole force between 2H2O is a special type of dipole-dipole force called Hydrogen bonding. Sulfur has more protons and electrons than Oxygen so you would think that the intermolecular force of 2H2S will be stronger than that of 2H2O and therefore the boiling point of 2H2S will be higher. Yet 2H2O has the higher boiling point and the reason is that 2H2O has a hydrogen bond while H2S does not since O is one of the highest electronegative atoms in the periodic table and it is bonded to an H atom of another molecule in 2H2O. And since Hydrogen bond is a stronger dipole-dipole force than that of a normal dipole-dipole bond the boiling point of water will be greater than that of hydrogen sulfide.
3. Iodine solid sublimes to Iodine gas. What happens in terms of intermolecular forces as this process occurs?
3. When the Iodine solid was placed directly in a temperature equal to its boiling point, the intermolecular forces between the Iodine molecules grew weaker. So the Iodine particles start to move away from each other. Therefore the Iodine solid sublimes to Iodine gas.
