The vapor pressure of a liquid at a particular temperature is the
partial pressure of the vapor over the liquid measured at equilibrium.
When a liquid is placed in a closed vessel, the partial pressure of its
vapor increases over time until
The water is attracted to the glass, so a thin film moves up the
surface of the glass. This action expands the surface area, so the
water column rises to counteract it. The process then repeats itself.
Surface tension also explains the developme
Unit Cell Continued
The structure of a covalent network solid is determined primarily by
the direction of the covalent bonds.
The structure of diamond is similar to that of ZnS, with a carbon atom
replacing each Zn2+ position (dark spheres) and each S2- p
At STP, carbon dioxide is never a liquid. That is why carbon dioxide
sublimes directly from solid to gas.
The phase diagram for sulfur shows some interesting characteristics.
The existence of two different solid structures for sulfur, rhombic and
Stoichiometry and Gas Volumes
Use the ideal gas law to find moles from a given volume, pressure,
and temperature, and vice versa.
When a 2.0-L bottle of concentrated HCl was spilled, 1.2 kg of CaCO 3
was required to neutralize the spill. What volume of CO
When the natural log (ln P) of the vapor pressure is plotted against
the reciprocal of temperature (1/T), a straight-line graph is obtained.
The next slide shows this graph for four liquids.
The ClausiusClapeyron equation describes these graph
Heat of Fusion
The heat of fusion, DHfus, is the heat needed to melt a solid. It is
given in kJ/mol.
For water, the phase change is represented by
H2O(s) H2O(l); DHfus = 6.01 kJ/mol
The heat of vaporization, DHvap, is the heat needed to vaporize a
The compounds are listed in order of increasing molar mass. We
would expect that the vapor pressures would decrease from top to
bottom, but this is not the case. The vapor pressures of water and
glycerol are much lower than anticipated.
London forces are also larger for more polarizable (more easily
On the next slide, each compound has the same chemical formula,
C5H12. However, in each compound, the carbon atoms are bonded in
a different structure. Not
The term van der Waals forces is a general term that includes both
dipole-dipole forces and London forces.
Polar molecules exhibit dipole-dipole forces that result in alignment of
the molecules. This phenomenon is illustrated below f
Explain the Tyndall effect.
Give examples of hydrophilic colloids and hydrophobic colloids.
Explain how micelles can form an association colloid.
A solution is composed of