Term
| What are the Strong IMF's? |
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Definition
| high boiling point, high melting point, high ΔHvap, high ΔHfus, high ΔHsub, low VP |
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Term
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Definition
| low boiling point, low melting point, low ΔHvap , low ΔHfus, low ΔHsub, high VP |
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Term
| what is a dipole-dipole force? |
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Definition
| a positive and a negative end of another molecule are attracted to each other |
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Term
which of the following molecules have dipole-dipole forces?
a) CO2
b) CH2Cl2
c) CH4
d) Cl4
e) CH3Cl
f) HCl |
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Definition
a) CO2 no
b) CH2Cl2 yes
c) CH4 no
d) Cl4 no
e) CH3Cl yes
f) HCl yes |
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Term
| what is an ion-dipole force? |
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Definition
| the attractive forces between an ion and a polar molecule |
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Term
| Which should have more negative hydration energy, Cl- or Br-? |
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Definition
| Br- is larger than Cl- so Cl- has the more negative ΔH hydration |
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Term
| what is a London Dispersion force? |
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Definition
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Term
what type(s) of intermolecular forces exist between each of the following molecules?
a) HBr
b) CCl4
c) PF3
d) PCl5
e) SO2
f) CS2
g) H2S |
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Definition
a) HBr = dispersion forces, dipole-dipole forces
b) CCl4 = dispersion forces
c) PF3 = dispersion forces, dipole-dipole forces
d) PCl5 = dispersion forces
e) SO2 = dispersion forces, dipole-dipole forces
f) CS2 = dispersion forces
g) H2S = dispersion forces, dipole-dipole forces |
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Term
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Definition
| a dipole-dipole interaction between the hydrogen atom in a polar N-H, O-H, or F-H bond and an electronegative O,N, or F atom |
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Term
Which of the following exhibits significant hydrogen bonding?
a) HBr
b) H2CF2
c) H2
d) CH3CN
e) CCl4
f) CH3CO2H
g) CH3COCH3
h) H2S
i) CH3CH2OH |
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Definition
a) HBr = no
b) H2CF2 = no
c) H2 = no
d) CH3CN = no
e) CCl4 = no
f) CH3CO2H = yes
g) CH3COCH3 = no
h) H2S = no
i) CH3CH2OH = yes |
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Term
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Definition
| the pressure of a vapor above a liquid at a given temperature |
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Term
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Definition
| the phase change from liquid to vapor |
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Term
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Definition
| the phase change from vapor to liquid |
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Term
| The molar enthalpy of vaporization of water is 40.7 kJ/mol at 100oC. How much energy is required to vaporize 925g of water at 100oC? (H2O = 18.02g/mol) |
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Definition
g --> mol --> kJ
925g x (1mol H2O/18.02g) x (40.7kJ/1mol H2O)
= 2.09 x 103kJ |
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Term
| Calculate the mass of water that can be vaporized at its boiling point with 155kJ of heat. (ΔHvap = 40.7kJ/mol) |
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Definition
kJ --> mol --> g
155kJ x (1mol H2O/40.7kJ) x (18.02g/1mol)
= 68.6g H2O |
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Term
| what is the Clausius-Clapeyron equation? |
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Definition
ln (P2/P1) = - (ΔHvap/R)(1/T2 - 1/T1)
R = gas constant (8.314 J/K mol) |
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Term
The vapor pressure of benzene C6H6, is 40.1mmHg at 7.6oC. What is the vapor pressure at 60.6oC?
(ΔHvap = 31.0kJ/mol) |
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Definition
ln (P2/P1) = - (ΔHvap/R)(1/T2 - 1/T1)
ln (P2/40.1mmHg) = - (31.0kJ/mol/8.314x10-3kJ/K mol)(1/333.6K - 1/218.6K)
ln (P2/40.1mmHg) = 2.11 (take the antilog of both sides)
P2/40.1mmHg = e2.11
P2 = e2.11 x 40.1mmHg
P2 = 331mmHg |
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