The document lists four substances and their boiling points in order of decreasing strength of intermolecular forces: sodium nitrate (NaNO3), ethylene glycol, ethylene chloride, and hydrogen bromide (HBr). Sodium nitrate has the highest boiling point of 380°C due to its ionic bonds, which require a large amount of energy to break. Ethylene glycol has the next highest boiling point of 197.3°C because it forms hydrogen bonds that are weaker than ionic bonds but still require energy to break. Ethylene chloride boils at 12.3°C as it only has dipole-dipole interactions holding the molecules together. Hydrogen bromide has the lowest boiling point of

1. Part Il. The remaining questions should be answered in this test booklet ould be answered in this
test booklet. Give Place the following substances in order of decreasing boiling point. Why? (6
points) 1 CH3CH2C f dncroasing strength of intermolecular forc
Solution
HBr boiling point =  -66 °C
ethylene chloride boiling point =12.3 °C
ethylene glycol boiling point =  197.3 °C
NaNO3 boiling point =  380 °C
Ionic bonds are very strong and it needs huge amount of energy will be needed to break them.
hence ionic compounds (NaNO3) have boiling points .
Ethylene glycol has hydrgen bond which less strong than ionic bonds and it needs energy to
break hydrogen bonds . hence it needs little less energy than ionic to boil.
Ethylene chloride has dipole dipole forces which are very mild forces. hence it needs less energy
to make them boil.