CH 13
The dissolution of water in octane (C8H18) is prevented by ________.
A- replusion between like-charged water and octane molecules
B- ion-dipole attraction between water and octane molecules
C- London dispersion forces between octane molecules
D- dipole-dipole attraction between octane molecules
E- hydrogen bonding between water molecules
hydrogen bonding between water molecues
Given the initial rate data for the reaction A + B -> C, determine the rate expression for the reaction.
[A] [B] delta [C]/delta t
0.125 0.105 1.23x10-1
0.125 0.315 3.69x10-1
0.250 0.105 1.23x10-1
A- delta [C]/delta t = 1.17[A]2[B]
B- delta [C]/delta t = 1.17[B]
C- delta [C]/delta t = 11.2[B]2
D- delta [C]/delta t = 75.0[B]
delta [C]/delta t = 1.17[B]
Consider the following reaction at equilibrium:
2NH3(g) <-> N2(g) + 3H2(g)
Le Chatelier's principle predicts that the moles of H2 in the reaction container will increase with:
A- an increase in total pressure by the addition of helium gas (V and T constant)
B- addition of some N2 to the reaction vessel (V and T constant)
C- some removal of NH3 from the reaction vessel (V and T constant)
D- a decrease in the total pressure (T constant)
E- a decrease in the total volume of the reaction vessel (T constant)
a decrease in the total pressure (T constant)
A reaction was found to be second order in carbon monoxide concentration. The rate of the reaction ________ is the [CO] is doubled, with everything else kept the same.
A- is reduced by a factor of 2
B- doubles
C- triples
D- increased by a factor of 4
E- decreased by a factor of 4
increased by a factor of 4
A solution with a concentration higher than the solubility is:
A-not possible
B-supersaturated
C-saturated
D-supercritical
E-unsaturated
Supersaturated
The partial pressure of oxygen in the air a diver breathes is too great, __________.
A- No problems result from this situation
B- the urge to breath is reduced and not enough CO2 is removed from the body
C- the urge to breathe is increased and excessive CO2 is removed from the body
D- respiratory tissue is damaged by oxidation
E- hyperventilation results
the urge to breath is reduced and not enough CO2 is removed from the body
What is the overall order of the reaction
CO(g) + NO2(g) -> CO2(g) + NO(g)
if it proceeds via the following rate expression?
delta [CO2]/delta t = k[CO][NO2]
second-order
At equilibrium,
A- the limiting reagent has been consumed
B- the value of the equilibrium constant is 1
C- all chemical reactions have ceased
D- the rates of the forward and reverse reactions are equal
E- the rate constants of the forward and reverse reactions are equal
the rates of the forward and reverse reactions are equal
_________ are used in automotvie catalytic converters.
A- Noble gases
B- Homogeneous catalysts
C- Heterogeneous catalysts
D- Nonmetal oxides
E- Enzymes
Heterogeneous catalysts
Of the following, a 0.3m aqueous solution of _____ will have the highest freezing point.
A- Fe(NO3)2
B- RbBr
C- (NH4)2SO4
D- Sr(NO3)2
E- K2SO4
RbBr
Lucy is making spaghetti for dinner. She places 2.97 kg of water in a pan and brings it to a boil. Before adding the pasta, she adds 24 grams of table salt to the water and again brings it to a boil. The temperature of the salty, boiling water is ________oC. Assume a pressure of 1.00 atm and negligible evaporation of water. Kb for water is 0.52oC/m
100.23
Rate constants usually:
A- are independent of time and temperature
B- decrease with time
C- increase with temperature
D- decrease with temperature
E- increase with time
increase with temperature
For the following reaction at equilibrium, in a reaction vessel, which one of the changes below would cause the Br2 concentration to decrease?
2NOBr(g) <-> 2NO(g) + Br2(g) delta H=30kJ
A- increase the temperature
B- compress the gas mixture into a smaller volume
C- increase the temperature
D- add a catalyst
E- add more NOBr
add more NOBr
Determine the freezing point (oC) of a 0.04 molal aqueous solution of MgSO4. Assume i=2.0 for MgSO4. The molal freezing-point depression constant of water is 1.86oC/m.
-0.149
The concentration (M) of HCl in a solution prepared by dissolving 6.7 grams of HCl in 200 grams of C2H6O is ________M. The density of the solution is 0.79 g/mL.
0.70M
The concentration of sodium chloride in an aqueous that is 3.62 M and that has a density of 1.01 g/mL is ________ % by mass.
20.9%
A->B (first order)
time(sec) [A], M/s
0 1.22
3 0.86
6 0.61
9 0.43
12 0.31
15 0.22
0.12
At 400.0K, the equilibrium constant (Kp) for the following reaction is 0.452.
2SO2(g) + O2(g) ->2SO3(g)
At equilibrium, the partial pressure of SO2 is 24.6 atm and that of O2 is 10.3 atm. The partial pressure of SO3 is ________ atm.
53.1
1.83 grams of polyethylene sample (nonelectrolyte) was dissolved in enough benzene to make 150. mL solution, and the osmotic pressure was found to be 1.24 torr at 25oC. What is the molar mass (g/mol) of polyethylene.
1.8x105
The vapor pressure of pure water at 25oC is 23.8 torr. Determine the vapor pressure (torr) of water at 25oC above a solution prepared by dissolving 22 grams of urea (a nonvolatile, non-electrolyte, MW = 60.0g/mol) in 150 grams of water.
17
A solution is prepared by dissolved 56.2 grams of CaCl2 in 125 grams of water. The density of the resulting solution is 1.02 g/mL. The concentration of CaCl2 is _____% by mass.
31.0%
For the first-order decomposition of N2O5 at 277K, where k = 4.3x10-3s-1, calculate the concentration after 205 seconds if the initial concentration is 0.055M
0.023 M
At 200oC, the equilibrium constant (Kp) for the reaction below is 2.40x103
2NO(g) <-> N2(g) + O2(g)
A closed vessel is charged with 36.1 atm of NO. At equilibrium, the partial pressure of O2 is _______ atm.
17.9
The rate constant of a first order process that has a half-life of 4.2 mins is s-1
0.00275
A first-order reaction has a rate constant of 0.54 min-1. It takes ________ min for the reactant concentration to decrease from 0.31 M to 0.16M.
1.2