Question

Intermolecular Forces and Physical Properties of Pure Substances

Which has the lowest normal boiling point?
N₂
CH₃CH₂CH₃
NaCl
Hg
Which has the lowest normal boiling point?
H₂O
CH₄
Li₂O
C₂H₆
Which has the smallest vapour pressure at 25°C?
H₂O
SiO₂
SO₂
O₃
Which has the least viscosity?
HOCH₂CHOHCH₂OH
CH₃(CH₂)₄CH₃
CH₃(CH₂)₃CH₃
CH₃CH₂OH
Which has the highest enthalpy of fusion?
H₂O
MgO
Li₂O
HF

Answer 1

N2 – 195.8 e CH3 CH₂ CH3 – 42° e. Nach – 1,465°e. Hg - 356.76 2 has the lowest boiling point as it behaves line inert molecule. Boiling point is a property which depends on intermolecular interaction of the molecule. As N is very stable and inert, es interaction with other molecule is less so to boiling point lowest H2O 100°c cita - 161.5°C Li₂O 2600 e CHE - 89°c comparing Cha, Cz to both are noupolar and have only Loudon dispersion forces. Bigger molecules have larger London forces hence city has less interections and less boiling points H₂O + 0.0313 atm. sio2 3.29810- afm. So. - 4.03 attor 03 = to atm. site has the lowest rapour pressure due to its structure Itin solid whether others are liquid, ges.

4) least viscosity is observed in CH3 (CH2) 3 CH3. because with increase in carbonchange and hydrogen bonding viscosity increarres. 420 334 J ngo 1880 j 420 - 597880] HF - 2738000 I Hf her the smallest enthalpy of fusson because it has the weakest intermolecular forces of attraction, dipolar forcesof attraction. These forces are easier to overcame than hydrogen bonding or ionie forces.