Harris Gurny
Chapter 14 review- Liquids and Solids
Properties of Liquids
1. indefinite shape, conforms to the shape of the container
2. limited compressability
3. Atoms/ molecules have more space in between them.
4. Atoms/ molecules are randomly orientated
Properties of Solids
1. Definite shape
2. Motion of atoms is limited
3. Atoms will be very close to each other
4. Atoms/ molecules have specific orientation to each other
Intermolecular forces- forces that occur between molecules that cause state change.
Order of Intermolecular forces from strongest to weakest
1. Hydrogen Bond
a. Occurs when hydrogen is bonded to a highly electromagnetic atom.
b. This causes a great polarity and a close approach of the dipoles.
c. Form of Dipole- Dipole bonding, but stronger.
d. Increases the boiling point, making the substance stay as a liquid for
longer.
2. Dipole = Dipole
a. Molecules with dipole moments attract each other by lining up so the
positive and negative end is close together.
b. Increases the boiling point, making the substance stay as a liquid for
longer.
3. London Dispersion Forces
a. Consists of two forces
i. Dipole = Induced Dipole
ii. Induced Dipole = Induced Dipole (weaker one)
b. London Dispersion Forces are the forces that exist between nonpolar ad
noble gas molecules.
c. Atoms can develop a temporary dipolar arrangement of change as the
electrons move around the nucleus. This can induce a dipole in a
neighboring atom.
d. Bond formed is weak and short lived
e. London Dispersion Forces lock atoms into place and produce solids.
Heating/ cooling curve
Phase changes of water, starting at solid and ending at gas
1. Solid, lower temperature
2. Melting Point- point where solid turns to liquid (273 K for water)
3. Liquid, high temperature
4. Boiling Point- liquid turns into gas (373 K for water)
5. Gas, even higher temperature
Phase changes of water, starting at gas and ending at solid
1. Gas, high temperature
2. Condensation point- Gas turns to liquid.
3. Liquid, lower temperature
4. Freezing point- liquid turns to solid
Water
1. Density of water in states, highest to lowest
a. Liquid
b. Solid
c. Gas
2. Since density is lower in the solid form of water, ice floats
3. Water expands as the temperature decreases.
Energy requirements for the changes of state
1. With more energy, the phase increases (from solid to liquid to gas)
2. Heat of Fusion
a. Amount of energy needed to make 1 gram of a solid become a liquid.
b. Q= mHf (the f is little and a triangle comes before it)
c. m means mass
d. Heat of Fusion of water is 334 J/g
3. Heat of Vaporization
a. Amount of energy needed to make 1 gram of a liquid become a gas.
b. Q= mHv (the v is little and a triangle comes before it)
c. m means mass
d. Heat of Vaporization of water is 2260 J/g
Example: Calculate the energy required to melt 8.5 g of ice at 273 K.
Q= (8.5 g)(334 J/g) = 2869 J
Another Equation: Q= mC(change in)T
1. m is mass
2. c is specific heat capacity
3. t is temperature
4. Tells you how much energy was used in a reaction
Evaporation and Vapor Pressure
1. Vaporization/evaporation- process in which molecules escape the liquids surface
and forms a gas.
2. This process requires energy
3. Vapor Pressure
a. In a close beaker with liquid, the process of condensation occurs
i. Condensation- process in which molecules become gas through
vaporization and then becomes a liquid again. Eventually, the same
number of molecules are leaving the liquid and returning to it;
constant.
ii. This causes the container to go into an equilibrium.
b. Vapor Pressure- the pressure of the vapor present at equilibrium with its
liquid.
c. Liquids with high vapor pressure evaporate rapidly. Thus, high vapor
pressure lowers the boiling point.
d. Liquids with large intermolecular forces have low vapor pressure, which
increases the boiling point
Boiling Point and Vapor Pressure
1. The vapor pressure of the water must be equal to the atmospheric pressure before
boiling can occur.
2. Thus, boiling point is not a specific value since it matters what the atmospheric
pressure is. Boiling point is a function of pressure
3. The atmospheric pressure increases as the altitude decreases, which increases the
boiling point.
Solids
1. Crystalline solids
a. Highly ordered arrangement of the components.
b. Three different types
i. Ionic Solids
1. Metal and nonmetal
2. Components are ions
3. Strong bonds.
4. NaCl (salt)
ii. Molecular solids
1. Components are molecules
2. Low melting points
iii. Atomic Solids
1. Components are a single atom
2. C – diamond
Alloy- mixture of metallic elements. It improves/ changes the physical and chemical
properties.