Identify which liquid will boil first, second, etc.?

Question

You are given three different compounds and must use your knowledge of INTERmolecular forces to determine the order that each compound will BOIL. You are given:
·Ammonia
·Octane
·(Liquid) Nitrogen (N2)
#1: Identify which liquid will boil first, second, etc.
why is it in that order?

Answer 1

it boils in the order N2 , Octane , Ammonia

N2 and octane are non-polar simple covalent molecule . Their intermolecular force are weak Van Der Waals Force . Bigger the molecular size , stronger the Van Der Waals force . So Octane with C8H18 has bigger molecular size than N2 will have higher boiling point that N2 .

NH3 is polar simple covalent molecule . It intermolecular force are hydrogen bonding . And Hydrogen bond > Van Der Waal . So NH3 has the highest boiling point .

Answer 2

If we are only looking at intermolecular forces, then ammonia boils last, since it has all those hydrogen bonds. Octane is next, since it has somewhat polar covalent bonds. Nitrogen boils lowest since it is non-polar. However, you might need to take weight into consideration. Octane is a lot heavier than the rest, so that might have an effect (heavier stuff tends to boil higher).

Answer 3

N2 first because of the least strong intermolecular forces (Van der Waals)

then Octane

then NH3 because of hydrogen bonding. Hydrogen bonding increase the boiling temp