At equilibrium
The rates of the forward and reverse reactions are equal
Which one of the following will change the value of equilibrium constant?
changing temperature
Which of the following expressions is the correct equilibrium constant expression for the equilibrium between dinotrogen tetraoxide and nitrogen dioxide?
[NO?]�/[N?O?]
The equilibrium constant expression depends on the ____ of the reaction.
stoichiometry
The equilibrium constant for reaction 1 is K. The equilibrium constant for reaction 2 is what?
(1 SO? (g) + (1/2)O? ? SO? (g)
(2 2SO? (g) ? 2SO? (g) + O? (g)
1/K�
The value of Keq for the following reaction is 0.25:
SO? (g) + NO? (g) ? SO? (g) + NO (g)
The value of Keq at the same temperature for the reaction below is what?
2SO? (g) + 2NO? (g) ? 2SO? (g) + 2NO (g)
0.063
The equilibrium expression for Kp for the reaction below is what?
N? (g) + O? (g) ? 2NO (g)
[NO]�/[N?][O?]
Which of the following expressions is the correct equilibrium constant expression for the reaction below?
HF (aq) + H?O (l) ? H?O? (aq) + F? (aq)
[H?O?][F?]/[HF]
The equilibrium constant for the gas phase reaction N? (g) +3H? (g) ? 2NH? (g) is Keq = 4.34 x 10?� at 300�C. At equilibrium ______.
Reactants predominate
The equilibrium constant for the gas phase reaction 2SO? (g) + O? (g) ? 2SO? (g) is Keq = 2.80 x 10� at 30� C. At equilibrium _____.
Products predominate
The equilibrium constant for the gas phase reaction N? (g) +O? (g) 2NO ? (g) is Keq = 4.20 x 10?�� at 30� C. At equilibrium _________.
Reactants predominate
Consider the following equilibrium.
2SO? (g) + O? (g) ? 2SO? (g)
The equilibrium cannot be established when ______ is/are placed in a 1.0 L container.
0.75 mol SO? (g)
How is the reaction quotient used to determine whether a system is at equilibrium?
The reaction is at equilibrium when Q = Keq
The reaction below is exothermic:
2SO? (g) + O? (g) ? 2SO? (g)
Le Chatelier's principle predicts that _______ will result in an increase in the number of moles of SO? (g) in the reaction container.
increasing the pressure
In which of the following reactions would increasing pressure at constant temperature not change the concentrations of reactants and products, based on Le Chetelier's principle?
N? (g) +2O? (g) ? 2NO? (g) noble gases
Consider the following reaction at equilibrium:
2NH? (g) ? N? (g) +3H? (g) delta H� = +92.4 kj
Le Chatelier's principle predicts that adding N? (g) to the system at equilibrium will result in _____.
A decrease in the concentration of H? (g)
Consider the following reaction at equilibrium:
2CO? (g) ? 2CO (g) +O? (g) delta H� = -514 kj
Le Chatelier's principle predicts that an increase in temperature will ______.
decrease the value of the equilibrium constant
Consider the following reaction at equilibrium:
2CO? (g) ? 2CO (g) +O? (g) delta H� = -514 kj
Le Chatelier's principle predicts that the equilibrium partial pressure of CO (g) can be maximized by carrying out the reaction ________.
at low temperature and low pressure
Consider the following reaction at equilibrium:
2SO? (g) + O? (g) ? 2SO? (g) delta H� = -99 kj
Le Chatelier's principle predicts that an increase in temperature will result in______.
a decrease in the partial pressure of SO?
The effect of a catalyst on equilibrium is to ________.
increase the rate at which equilibrium is achieved without changing the composition of the equilibrium mixture
A reaction vessel is charged with hydrogen iodide, which partially decomposes to molecular hydrogen and oidine:
2HI (g) ? H? (g) + I? (g)
When the system comes to equilibrium at 425 �C, Phi = 0.708 atm, and Ph? = 0.0960 atm. The value of Kp at this temper
1.84 x 10?�
Given the following reaction:
CO (g) +2H? (g) ? CH?OH (g)
In an experiment, 0.42 mol of CO and 0.42 mol of H? were placed in a 1.00-L reaction vessel. At equilibrium, there were 0.29 mol of CO remaining. Keq at the temperature of the experiment is _______
17.5
The equilibrium constant expression for a reaction written in one direction is the ________ of the one for the reaction written in the reverse direction.
Reciprocal
If Reaction A + Reaction B = Reaction C, then Kc Reaction C = ________.
Kc Reaction A x Kc Reaction B
If the value for the equilibrium constant is much greater than 1, then the equilibrium mixture contains mostly ______.
Products
Pure ________ and pure ______ are excluded from equilibriul constant expressions.
Solids, liquids
The number obtained by substitution starting reactant and product concentrations into an equilibrium constant expression is known as the ________.
Reaction quotient
If the reaction quotient Q for a reaction is less than the value of the equilibrium constant K for that reaction at a given temperature, __________ must be converted to _________ for the system to reach equilibrium.
reactants, products
If the reaction quotient Q for a reaction is greater than the value of the equilibrium constant K for that reaction at a given temperature, __________ must be converted to _________ for the system to reach equilibrium.
products, reactants
For an exothermic reaction, increasing the reaction temperature results in a(n) ______ in K.
decrease
If a reaction is endothermic, ________ the reaction temperature results in an increase in K.
Increasing
If a substance is added to a system at equilibrium, the system reacts to _________ some of the substance.
consume
If a substance is removed from a system, the system reacts to ______ of a substance.
produce more
At constant temperature, reducing the volume of a gaseous equilibrium mixture causes the system to shift in the direction that __________ the number of moles of gas.
reduces
At constant temperature, increasing the volume of a gaseous equilibrium mixture causes the system to shift in the direction that __________ the number of moles of gas.
increases
If the temperature of a system at equilibrium is increased, the system reacts as if we added a ________ to an endothermic reaction or a _______ to an exothermic reaction.
reactant, product
The equilibrium shifts in the direction that consumes the _______ namely heat.
excess reactant
Increasing T in an endothermic reaction causes the equilibrium to shift _____.
right
Increasing T in an exothermic reaction causes the equilibrium to shift _____.
left
Decreasing T in an endothermic reaction causes the equilibrium to shift _____.
left
Decreasing T in an exothermic reaction causes the equilibrium to shift _____.
right
The relationship between the concentrations of reactants and products of a system at equilibrium is given by the __________
law of mass action
A catalyst increases the rate at which equilibrium is achieved but does not change _______
the composition of the equilibrium mixture
At constant temperature, reducing the volume of a gaseous equilibrium mixture causes the reaction to shift in the direction that _________ the number of moles of gas in the system
decreases
In an exothermic equilibrium reaction, increasing the reaction temperature favors the ________
formation of reactants
Le Chatelier's principle states that if a system at equilibrium is disturbed, the equilibrium will shift to ________.
minimize the disturbance
The relationship of absorbed light to the concentration of the substance absorbing the light is governed by __________.
Beer's law
For the reaction aA +bB ? cC +dD, the rate law is _________.
[A]^a[B]^b
If a rate law is second order (reactant), doubling the reactant _________ the reaction rate
Quadruples
Reaction rates are affected by reactant concentrations and temperature. This is accounted for by the ______.
Collision model
The minimum energy to initiate a chemical reaction is the _________ energy.
activation
Reaction rate data showing temperature dependence obey an equation devised by _________.
Arrhenius
The number of molecules that particupate as reactants defines the ___________ of the reaction.
Molecularity
Elementary reactions involving the simultaneous collision of three molecules are ________
termolecular
A catalyst that is present in the same phase as the reacting molecules is called a ________ catalyst
homogeneous
The binding of molecules to the surface of a catalyst is referred to as ________.
adsorption
The uptake of molecules into the interior of another substance is referred to as _______.
absorption
Rates of reaction _______ be positive or negative.
cannot
The instantaneous rate of a reaction ______ be read directly from the graph of molarity versus time at any point on the graph
cannot
The overall reaction order ____ the sum of the orders of each reactant in the rate law.
is
Units of the rate constant of a reaction _____ independent of the overall reaction order.
are not
The concentrationof reactants or products at any time during the reaction ____ calculated from the integrated rate law.
can be
The rate of a second order reaction ________ on the concentrations of more than one reactant
can depend
The half-life for a first order rate law ________ on the starting concentration.
doesn't depend
The rate limiting step in a reaction is the ________ step in the reaction sequence.
slowest
Consider the following reaction 3A?2B
The average rate of appearance of B is given by delta B/delta t. Comparing the rate of appearance of B and the rate of disappearance of A, we get delta B/delta t = ___________ x(-delta A/delta t)
+2/3
Which substance in the reaction below either appears or disappears the fastest?
4NH? +7O? ? 4NO? + 6H?O
O?
Consider the following reaction:
A?2C
The average rate of appearance of C is given by delta C/delta t. Comparing the rate of appearance of C and the rate of disappearance of A we get delta C/delta t = ________x (-delta A/delta t)
+2
A flask is charged with 0.124 mol of A and allowed to react to form B according the the reaction A(g) ? B(g). The following data are obtained for [A] as the reaction proceeds:
Time(s) 0.00 10.00 20.0 30.0 40.0
Moles of A 0.124 0.110 0.088 0.073 0.054
The
2.2 x 10?�
A flask is charged with 0.124 mol of A and allowed to react to form B according the the reaction A(g) ? B(g). The following data are obtained for [A] as the reaction proceeds:
Time(s) 0.00 10.00 20.0 30.0 40.0
Moles of A 0.124 0.110 0.088 0.073 0.054
The
1.7 x 10?�
A flask is charged with 0.124 mol of A and allowed to react to form B according the the reaction A(g) ? B(g). The following data are obtained for [A] as the reaction proceeds:
Time(s) 0.00 10.00 20.0 30.0 40.0
Moles of A 0.124 0.110 0.088 0.073 0.054
The
+1.5 x 10?�
A flask is charged with 0.124 mol of A and allowed to react to form B according the the reaction A(g) ? B(g). The following data are obtained for [A] as the reaction proceeds:
Time(s) 0.00 10.00 20.0 30.0 40.0
Moles of A 0.124 0.110 0.088 0.073 0.054
How
0.014
At elevated temperatures, dinitrogen pentoxide decomposes to nitrogen dioxide and oxygen:
2N?O? (g) ? 4NO? (g) + O? (g)
When the rate of formation of NO? is 5.5 x 10?? M/s, the rate of decomposition of NO
2.8 x 10??
At elevated temperatures, methylisonitrile (CH?NC) isomerizes to acetonitrile (CH?CN):
CH?NC (g) ? CH?CN (g)
At the start of the experiment , there are 0.200 mol of reactant and 0 mol of product in the reaction vessel. After 25 min of reaction, 0.108 mol
3.7 x 10?�
A reaction was found to be second order in carbon monoxide concentration. The rate of the reaction _________ if [CO] is doubled, with everything else kept the same.
increases by a factor of 4
The overall order of a reaction is 1. The units of the rate constant for the reaction are _________.
1/s
The overall order of a reaction is 2. The units of the rate constant for the reaction are _________.
1/Ms
The kinetics of the reaction below were studied and it was determined that the reaction rate increased by a factor of 9
...
A catalyst that is present in a different phase as the reacting molecules is called a ________ catalyst
heterogeneous
Increasing pressure ________ volume, and favors _________.
decreases, products
Decreasing pressure ________ volume, and favors _________.
increases, reactants