Donna Narsavage Heald Siena College Loudonville, NY 2006, Prentice-Hall Midterm Review Nuclear Chemistry Gas Laws Intermolecular Forces Colligative Properties Chemical Equilibrium Chemistry, The Central Science, 10th edition Theodore L. Brown, H. Eugene LeMay, Jr., and Bruce E. Bursten
0. Midterm Review Nuclear Chemistry Gas Laws Intermolecular Forces Colligative Properties Chemical Equilibrium. Chemistry, The Central Science , 10th edition Theodore L. Brown, H. Eugene LeMay, Jr., and Bruce E. Bursten. Donna Narsavage Heald Siena College Loudonville, NY - PowerPoint PPT Presentation
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Donna Narsavage HealdSiena CollegeLoudonville, NY 2006, Prentice-Hall
Midterm ReviewNuclear Chemistry
Gas LawsIntermolecular ForcesColligative PropertiesChemical Equilibrium
Chemistry, The Central Science, 10th edition
Theodore L. Brown, H. Eugene LeMay, Jr., and Bruce E. Bursten
What change in the mass number of a nucleus occurs when the nucleus emits an alpha particle?
1. Mass number decreases by 1.
2. Mass number decreases by 2.
3. Mass number decreases by 4.
4. Mass number does not change.
What change in the mass number of a nucleus occurs when the nucleus emits an alpha particle?
1. Mass number decreases by 1.
2. Mass number decreases by 2.
3. Mass number decreases by 4.
4. Mass number does not change.
1. Yes
2. No
1. Yes
2. No
Bonus:
1. Alpha rays most efficiently pass through the window.
2. Beta rays most efficiently pass through the window.
3. Gamma rays most efficiently pass through the window.
Bonus:
1. Alpha rays most efficiently pass through the window.
2. Beta rays most efficiently pass through the window.
3. Gamma rays most efficiently pass through the window.
Indicate the number of protons (p) and neutrons (n) in the radioactive nucleus represented by: 60
A container holds a mixture of oxygen, neon, and helium gases whose partial pressures are 150 torr, 300 torr, and 450 torr, respectively. The mole fraction of neon is
1. 0.172. 0.333. 0.504. 0.67
totali PP i
Correct Answer:
Xi = Pi/Ptotal
Xi = (300 torr)/(150 + 300 + 450) torr
Xi = 300 torr/900 torr = 0.33
totali PP i1. 0.172. 0.333. 0.504. 0.67
An unknown gas effuses at half the rate of helium. This gas is likely to be which of the following?
1. H2
2. CH4
3. Ne4. O2
5. Ar
1
2
M
M
2
1
r
r
Correct Answer:
(r1/2)2 =M2/M1
M2= (r1/r2)2M1
M2= (2/1)2(4.0 g/mol) = 16.0 g/mol
Therefore it could be CH4
1. H2
2. CH4
3. Ne4. O2
5. Ar
Real gases deviate from ideal behavior at __________ and _________.
1. High temperature; low pressure
2. Low temperature; high pressure
3. High temperature; high pressure
4. Low temperature; low pressure
Correct Answer:
At low temperature and high pressure, intermolecular forces increase as the molecules get closer together.
1. High temperature; low pressure
2. Low temperature; high pressure
3. High temperature; high pressure
4. Low temperature; low pressure
Which of the following molecules can hydrogen bond with itself?
1. 1, 22. 2, 33. 3, 44. 1, 2, 35. 1, 2, 3, 4
CH2F2 NH3 CH3-O-H CH3C CH3
O
1 2 3 4
Which of the following molecules can hydrogen bond with itself?
1. 1, 22. 2, 33. 3, 44. 1, 2, 35. 1, 2, 3, 4
CH2F2 NH3 CH3-O-H CH3C CH3
O
1 2 3 4
Arrange the following according to increasing vapor pressure.
1. NH3 < I2 < Br2 < CH4
2. I2 < Br2 < NH3 < CH4
3. NH3 < CH4 < I2 < Br2
4. NH3 < I2 < CH4 < Br2
5. CH4 < NH3 < Br2 < I2
NH3 I2 Br2 CH4
Arrange the following according to increasing vapor pressure.
1. NH3 < I2 < Br2 < CH4
2. I2 < Br2 < NH3 < CH4
3. NH3 < CH4 < I2 < Br2
4. NH3 < I2 < CH4 < Br2
5. CH4 < NH3 < Br2 < I2
NH3 I2 Br2 CH4
Which statement is true?
1. Boiling point ~120°C2. Boiling point ~95°C 3. Boiling point ~75°C4. Melting point ~95°C5. Melting point ~75°C
0
200
400
600
800
Vap
or
Pre
ssu
re (
mm
Hg
)
25 50 75 100Temperature (° C)
0
Which statement is true?
1. Boiling point ~120°C2. Boiling point ~95°C 3. Boiling point ~75°C4. Melting point ~95°C5. Melting point ~75°C
0
200
400
600
800
Vap
or
Pre
ssu
re (
mm
Hg
)
25 50 75 100Temperature (° C)
0
Of the following substances, predict which has the highest boiling point based on intermolecular forces.
Each of these molecules has almost the same molecular weight; however, acetonitrile has the largest dipole moment (3.9 D) and hence the largest dipole-dipole forces. Thus it has the highest boiling point.
Of the following substances, predict which has the lowest boiling point based on London dispersion forces.
1. He2. Ne3. Ar4. Kr5. Xe
Correct Answer:
More massive species have more polarizability and stronger London dispersion forces; consequently, amongst the noble gases He has the lowest boiling point.
1. He2. Ne3. Ar4. Kr5. Xe
Which one of the following phase changes is an exothermic process?
How much energy is required to raise the temperature of 1800. g ice at 0°C to 10°C? Hfus = 6.01 kJ/mol, heat capacity of water is 75.2 J/mol-K.
1. 60.1 kJ2. 75.2 kJ3. 135 kJ4. 601 kJ5. 676 kJ
Correct Answer:
There are 100 moles of ice, so the enthalpy of fusion is:H =(6.01 kJ/mol)(100 mol) = 601 kJ.To raise the water temperature 10°C requires q = (75.2 J/mol-K)(100 mol)(10°C ) = 75.2 kJ. Total energy = 601 kJ +75 kJ = 676 kJ
1. 60.1 kJ2. 75.2 kJ3. 135 kJ4. 601 kJ5. 676 kJ
Temperature
Pre
ssu
reAA
DD
CC
BB
In the unlabeled phase diagram below, the line segment from A to B separates which two phases?
1. Gas-liquid2. Liquid-solid3. Solid-gas
Correct Answer:
1. Gas-liquid2. Liquid-solid3. Solid-gas
Temperature
Pre
ssu
reAA
DD
CC
BB
Diamond and graphite are examples of which type of crystalline solids?
Ethanol normally boils at 78.4°C. The boiling point elevation constant for ethanol is 1.22°C/m. What is the boiling point of a 1.0 m solution of CaCl2 in ethanol?
1. 77.2°C2. 79.6°C3. 80.8°C
4. 82.1°C5. 83.3°C
Correct Answer:
The increase in boiling point is determined by the molality of total particles in the solution. Thus, a 1.0 m solution of CaCl2 contains 1.0 m Ca2+ and
2.0 m Cl for a total of 3.0 m. Thus, the boiling point is elevated 3.7°C, so it is 78.4°C + 3.7°C = 82.1°C.
mKT bb
1. 77.2°C2. 79.6°C3. 80.8°C4. 82.1°C5. 83.3°C
Which of the following is not an example of a colloid?
1. Fog2. Smoke3. Paint4. Milk5. Carbonated water
Correct Answer:
Carbonated water is a solution; all the other substances in the list are excellent examples of colloids.
1. Fog2. Smoke3. Paint4. Milk5. Carbonated water
What is Kp in terms of Kc for the following reaction ?
1. Kp = KcRT
2. Kp = Kc(RT)
3. Kp = KcR/T
4. Kp = Kc
5. Kp = Kc/(RT)2
2NO (g) + O2 (g) 2NO2 (g)
What is Kp in terms of Kc for the following reaction ?
1. Kp = KcRT
2. Kp = Kc(RT)
3. Kp = KcR/T
4. Kp = Kc
5. Kp = Kc/(RT)2
2NO (g) + O2 (g) 2NO2 (g)
What is the correct equilibrium constant expression for the reaction:
P4 (s) + 6Cl2 (g) 4PCl3 (l)
What is the correct equilibrium constant expression for the reaction:
P4 (s) + 6Cl2 (g) 4PCl3 (l)
Which accurately reflects the changes in concentration that will occur if O2 is added to disturb the equilibrium?
[NO] [O2] [NO2]
1. Increase Increase Increase
2. Increase Increase Decrease
3. Decrease Decrease Decrease
4. Decrease Decrease Increase
5. Decrease Increase Increase
2NO (g) + O2 (g) 2NO2 (g)
NO NO2
Which accurately reflects the changes in concentration that will occur if O2 is added to disturb the equilibrium?
[NO] [O2] [NO2]
1. Increase Increase Increase
2. Increase Increase Decrease
3. Decrease Decrease Decrease
4. Decrease Decrease Increase
5. Decrease Increase Increase
2NO (g) + O2 (g) 2NO2 (g)
NO NO2
Which of the following will result in an equilibrium shift to the right?
1. Increase temperature/increase volume
2. Increase temperature/decrease volume
3. Decrease temperature/increase volume
4. Decrease temperature/decrease volume
5. None of the above
PCl3 (g) + Cl2 (g) PCl5 (g) H° = -87.9 kJ/mol
PCl5
Which of the following will result in an equilibrium shift to the right?
1. Increase temperature/increase volume
2. Increase temperature/decrease volume
3. Decrease temperature/increase volume
4. Decrease temperature/decrease volume
5. None of the above
PCl3 (g) + Cl2 (g) PCl5 (g) H° = -87.9 kJ/mol
PCl5
What is the value of Kc for the reaction?
1. Kc = 1/(5.0 x 1018)1/2
2. Kc = 1/(2.5 x 1018)
3. Kc = -(5.0 x 1018)/2
4. Kc = -(5.0 x 1018)1/2
5. Kc = 2/(5.0 x 1018)1/2
2CO(g) + O2(g) 2CO2(g) Kc = 5.0 x 1018 at 25 °C
CO2(g) CO(g) + 1/2 O2(g) Kc = ?? at 25 °C
What is the value of Kc for the reaction?
1. Kc = 1/(5.0 x 1018)1/2
2. Kc = 1/(2.5 x 1018)
3. Kc = -(5.0 x 1018)/2
4. Kc = -(5.0 x 1018)1/2
5. Kc = 2/(5.0 x 1018)1/2
2CO(g) + O2(g) 2CO2(g) Kc = 5.0 x 1018 at 25 °C
CO2(g) CO(g) + 1/2 O2(g) Kc = ?? at 25 °C
For the gas-phase reaction A Bthe forward reaction rate is 3.0 104 s1 and the reverse reaction rate is 1.5 102 s1. What is the value of the equilibrium constant, Keq?
1. 0.022. 503. 0.0004
4. 2500
Correct Answer:
r
fc k
kK
0.021.5x10
3x102-
-4
cK
1. 0.022. 503. 0.0004
4. 2500
1. no bubbles are observed in the reaction mix.
2. the temperature of the reaction mix cools.
3. the concentrations of reactants and products no longer change.
4. the color of the reaction mix remains constant.
1. no bubbles are observed in the reaction mix.
2. the temperature of the reaction mix cools.
3. the concentrations of reactants and products no longer change.
4. the color of the reaction mix remains constant.
1. Kc is 2nd order with respect to NO2 and 1st order with
respect to N2O4.
2. Kc is independent of the starting concentrations of
reactants and products.
3. Kc is 2nd order with respect to NO2 and inversely
related to N2O4.
4. Kc is directly related to NO2 and inversely related to
N2O4.
1. Kc is 2nd order with respect to NO2 and 1st order with
respect to N2O4.
2. Kc is independent of the starting concentrations of
reactants and products.
3. Kc is 2nd order with respect to NO2 and inversely
related to N2O4.
4. Kc is directly related to NO2 and inversely related to
N2O4.
1. Kp = 1/[H2Og]
2. Kp = PH2O
3. Kp = [H2Og]
4. Kp = 1/PH2O
1. Kp = 1/[H2Og]
2. Kp = PH2O
3. Kp = [H2Og]
4. Kp = 1/PH2O
1. cannot determine without information about energy of reaction.
2. cannot determine without information about reaction rate constant.
3. no.
4. yes.
1. cannot determine without information about energy of reaction.
2. cannot determine without information about reaction rate constant.