Forces

In order to find the polarity of DEET, the electronegativity difference between the bond must be found. To measure electronegativity difference between the bonds of DEET, the smaller electronegativity is subtracted from the larger one. If the electronegativity difference between the bond is 0 - 0.4, it is a non polar covalent bond. If the electronegativity difference ranged from 0.5 to 1.7, the bond is a polar covalent bond. The electronegativity difference calculated in DEET, is displayed below;

C-H: 2.6 - 2.2 = 0.4 → Nonpolar Covalent
O-C: 3.4 - 2.6 = 0.8 → Polar Covalent
N-H: 3.0 - 2.2 = 0.8 → Polar Covalent

After calculating the electronegativity of DEET, the overall polarity of the compound would be polar, However, after looking at the lewis dot diagram, it can be seen that it is not polar since it cancels each other out. This means the bonds within the molecules are polar but overall, DEET is not polar. Bond dipole occurs when the electronegativity difference between two bonded atoms makes one side more negative and the other more positive. In the bond between carbon and hydrogen in DEET, carbon has a higher electronegativity which causes it to be negative and hydrogen becomes positive. In the bond between oxygen and carbon, oxygen has a higher electronegativity which gives it a negative charge and carbon has a positive charge. In the bond between nitrogen and hydrogen, nitrogen has a higher electronegativity so it has a negative charge and hydrogen has a positive charge. These molecules will line up and the attraction between positive and negative dipoles occurs. DEET is insoluble in water, making it a solid compound. The insolubility of DEET can be explained by the ‘like dissolves like’ theory. This theory states that polar substances will dissolve only polar substances and non polar substances will only dissolve nonpolar substances. Since water is polar and DEET is nonpolar, they cannot dissolve. DEET reacts very well with Benzene since it also also a nonpolar substance. DEET reacts and is compatible with most things other than strong oxidizing agents, strong acids and strong bases. Another intermolecular force DEET contains is hydrogen bonding. In order for hydrogen bonding to occur, a hydrogen atom must be bonded to an electronegative atom and there must be at least one lone pair of electrons on the electronegative atom bonded to the hydrogen. Hydrogen bonding is not present in DEET even though hydrogen is bonded to carbon, a very electronegative atom. Hydrogen bonding is missing because the carbon does not contain any lone pairs. Van der Waals Forces are intermolecular forces that control physical, behaviour or molecular substances. Just like everything else on this planet, DEET also contains Vander Waals Forces. London Dispersion forces are momentary attraction between dipoles. Everything in this world has London forces. DEET has a large amount of London forces because this force increases as the number of electrons increases and DEET has approximately 76 electrons. The boiling point is 110-112 degrees celsius. The boiling point of DEET is so high because since there are a lot of intermolecular forces present, there will be more attraction between the electrons which leads to an increased boiling point. Since DEET contains a large amount of electrons, the boiling point will increase due to more London forces. The boiling point of DEET is also fairly high due to the amount of carbons it contains. The melting point of DEET is about -45 degrees celsius.