MISC
What are the three states of matter? and which ones have a fixed volume?
Solid, liquid, gas
solid and liquid
What are the 3 intermolecular forces in order of increasing strength?
-London dispersion forces
-dipole-dipole
-Hbond
How are boiling points affected by intermolecular forces?
Stronger intermolecular forces between molecules make it more difficult for those molecules to be pulled apart. Therefore, stronger intermolecular forces result in higher boiling points.
What are the four types of crystalline solids?
Ionic: solid structure composed of ions arranged in a 3D structure and held together by ionic bonds (e.g., CaCl2);
Molecular: solid structure composed of covalent molecules held together by intermolecular forces (e.g., ice);
Covalent network: solid structure made up of covalently bonded atoms in a 3D arrangement (e.g., diamond);
Metallic: 3D arrangement of metallic atoms held together by a cloud of electrons over the array of atoms (e.g., steel)
What is a surfactant?
Surface Tension is reduced by the presence of dissolved substances called surfactants.
soap or detergent
Define a dipole-dipole interaction? What type of molecule does it need to be?
_attractive forces between polar molecules (pure substance or mixture)__
Which elements bonded with hydrogen create an H bond?
H-ONF
List the following molecules in order of increasing boiling point: Br2, F2, I2, Cl2,
F2, Cl2, Br2, I2
Ionic, molecular, covalent
Define surface tension and viscosity. How do intermolecular forces affect these properties (i.e., as intermolecular forces increase, what happens to each property?
Surface tension is the resistance of a liquid to spread out. Viscosity is a measure of a substance’s resistance to flow. As the strength of IMF’s increase, surface tension and viscosity increase. Molecules are more strongly attracted to each other and will be less likely to spread apart or to flow.
List the 6 types of phase changes with their reverse
Solid liquid: __melting__________
Liquid gas: ___boiling__________
Solid gas: ___sublimation_______
Reverse: ___freezing____________
Reverse: ___condensing_________
Reverse: ___deposition__________
What are the IMF's
H2
Just London!
Which of the following
molecules can form
hydrogen bonds?
H2 CH4 NH3 HF CH3OH
NH3 HF CH3OH
What crystal is the most strong?
Covalent-diamond
Can water and carbon
tetrachloride form a
solution?
No because water is polar and ccl3 is not
LIKE W LIKE
The energy of motion is ______ energy
As temperature increases it _____
kinetic!
increases
List all the IMF's in
NH3
HBond, London, dipole
Which of the following polar compounds is likely to have the highest boiling point?
a. CH3OCH3 d. H2CO b. CH3CH2OH e. CO
c. (CH3)2CO
B
Arrange the order of
melting points for the
following solids,
highest to lowest:
CH4 C6H14 C2H6 C4H10
C6H14 > C4H10 > C2H6 >CH4
Draw the cooling curve
show pic!
Draw the heating curve!
show pic!
List the following substances in order of increasing boiling points: BaCl2, H2, CO, HF, Ne, CO2
H2 <Ne<CO2 <CO<HF<BaCl2
List the following molecules in order of increasing surface tension: C3H8, CH4, CH3COOH, C2H6
Higher surface tension corresponds to stronger intermolecular forces. Go through the list above.
1. One of these (CH3COOH) has the ability to hydrogen-bond. It will probably have the strongest intermolecular forces.
2. CH3COOH is the only one of these molecules to have a dipole, and we already decided it hasthe strongest intermolecular forces.
3. Of the molecules that are left, the largest one (C3H8) likely has the strongest London dispersion forces. The smallest (CH4) likely has the weakest intermolecular forces. The answer is: CH4, C2H6, C3H8, CH3COOH
As intermolecular forces increases vapor pressure _____
decreases