Chapter 7
If heat is consumed during a reaction, there action is said to be________
ENDOTHERMIC
Consider the reaction shown: 452kcal+4PCl5(s)→P4(s)+10Cl2(g) This reaction is________because the sign of ΔHis________.
ENDOTHERMIC; Positive
Theconceptoffreeenergyallowspredictionofspontaneityofaprocessbyconsideringthechangesin________and________during the process.
ENTHAPY; ENTROPY
A reaction is said to be ________ if the bonds formed during there action are stronger than the bonds broken.
Exothermic
Activation Energy Can Best Be Described As
the difference in energy between reactants and the maximum energy.
Which factors would decrease the rate of a reaction? I. Lowering the temperature II. Increasing the concentration of reactants III. Adding a catalyst
1 only
Consider the reaction shown :P4(s)+10Cl2(g)→ 4PCl5(s)+ 452kcal When 50.00 g of P4 react,________kcal will be________.
182.4; Produced
Consider the reaction shown: 304.0kcal+ 4PCl3(l)→P4(s)+6Cl2(g) When 50.00 g of PCl3 react,________ kcal will be________.
27.67; Consumed
N2+O2→2NO ΔH=43.2kcal Based on the reaction shown, which statement is true?
43.2 kcal are consumed when 1.00 mole of O2 reacts.
S+O2 → SO2+ 70.8kcal Based on the reaction shown,which statement is true?
70.8 kcal are produced when 32.1 g of sulfur reacts.
S+O2→SO2 ΔH=-70.8kcal Based on the reaction shown, which statement is true?
70.8 kcal are produced when 32.1 g of sulfur reacts.
Consider the reaction shown: N2+O2→2NO ΔH=43.2 kcal When 50.0g of N2 react, ________ kcal will be________.
77.1; Consumed
For the reaction given below, what quantity of heat will be produced if 90g of C3H8 are consumed in the reaction? C3H8 + 5O2→ 3CO2 + 4H2O + 488kcal
996 kcal
For a chemical reaction to occur, all of the following must happen except
A large enough number of collisions must occur.
A processor reaction which takes in heat from the surroundings is said to be
Endothermic.
All of the statements concerning free energy and spontaneity are true except
Enthalpy and entropy are of equal importance in determining the spontaneity of a reaction.
In The Reaction Energy Diagrams Shown, reaction A is ________, and it occurs________reaction B. GRAPH
Exergonic; Slower Than
A processor reaction which releases heat to the surroundings is said to be
Exothermic
A rapid reaction is distinguished by
Having a small value of activation energy.
Which factors would increase the rate of a chemical reaction? I. Increasing the temperature II. Removing products as they are formed III. Adding a catalyst
I ,II,and III
Which of the following processes involve an increase in entropy?
I, V
All of the statements regarding the symbol ΔG are true except
It allows us to identify an EXOTHERMIC reaction.
All of the statements regarding the symbol ʺΔHʺ are correct except
It can be called entropy change.
Which statement best describes the way a catalyst works?
It decreases the value of E act.
To simplify comparisons, the energy value of fuels is expressed in units of
KCal/g.
Which change to this reaction system would cause the equilibrium to shift to the right?N2(g) +3H2(g) <---> NH3(g)+ heat
Lowering the temperature
In the process of dissolving sugar in water, the entropy increases. This means that the sign of ΔS is________, and that the randomness of the system________.
Positive; Increases
2SO2(g) + O2(g) <------> 2SO3(g)+ heatK= 4.8×10^27 Which statement about this system is not true?
Removing O2 will cause an increase in the amount of SO3.
For the following reaction, increasing the pressure will cause the equilibrium________ 2SO2(g) +O2 (g)<-----> 2SO3(g)+heat
Shift to the right, towards products.
The position of the equilibrium for a system where K=4.6×10^-15 can be described as being favored to ________; the concentration of products is relatively________.
The Left; Small
Consider the end other micreaction :N2(g)+2H2(g)→N2H4(l) The entropy change of this reaction is ________ and the enthalpy change is ________, so at a very high temperature, this reaction is probably________.
Unfavorable; Unfavorable; Nonspontaneous
P4(s)+10Cl2(g)→4PCl5(s) ΔH=-435.2kcal Based on the reaction shown,which statement is true?
When 1 mol P4(s) reacts, 435.2 kcal are released.
4PCl3(l)→P4(s)+6Cl2(g) ΔH=304.0kcal Based on the reaction shown,which statement is true?
When 1mol P4(s) is produced, 304.0 kcal are consumed.
Consider the reaction: 2CO(g) + O2(g)<--->2CO2(g) The equilibrium expression for this reaction is
[CO2]^2/ [CO]^2 [O2]
Consider the reaction: A+2B<----->2C+D The equilibrium expression for this reaction is
[C]2[D] / [A][B]2
A process which is unfavorable with respect to ENTHALPY, but favorable with respect to ENTROPY
could occur at high temperatures, but not at lower temperatures.
A reaction which is unfavorable with respect to ENTROPY, but favorable with respect to ENTHALPY
could occur at low temperatures but not at higher temperatures.
Which process is not likely to be considered reversible?
cutting down a tree
In the reaction A+B→AB, which of the following will not increase the rate?
decreasing the temperature
In the reaction energy diagrams shown, reaction B is________, and it occurs________ reaction B. 2 graphs with free energy on the y-axis and reaction on the x-axis
endergonic; faster than
Consider the reaction shown :2CO(g)+O2(g)→CO2(g)+ 135.2 kcal This reaction is________because the sign of ΔHis________.
exothermic; negative
Consider the reaction shown:C3H8+5O2→3CO2+4H2O+488kcal We can say that this reaction is________and that the sign of ΔHis________.
exothermic; negative
The function of a catalyst in a reaction system is to
increase the rate of the reaction.
Diatomic nitrogen is added to the equilibrium system: N2(g)+H2(g)<-------->2NH3(g)+heat When a new equilibrium is established the concentration of H2 will be ________the amount at the original equilibrium, and the amount of NH3 will be________the amount at the original equilibrium.
less than; greater than
2Al2O3(s)→4Al(s)+3O2(g) ΔG=+138 kcal Consider the contribution of entropy to the spontaneity of this reaction. As written, the reaction is________, and the entropy of the system________.
non-spontaneous; Increases
A reaction that is spontaneous can be described as
proceeding without external influence once it has begun.
The scientific principle which explains the observation that the amount of heat transfer accompanying a change in one direction is numerically equal but opposite in sign to the amount of heat transfer in the opposite direction is
the Law of Conservation of Energy.
Entropy can be defined as
the amount of disorder in a system.
When are action system is at equilibrium
the rates of the reaction in the forward and reverse directions are exactly equal.
All of the statements are true for spontaneous reactions except
the reaction rate is determined by the value of ΔG.
Reaction rates are determined by all of the following factors except
the spontaneity of the reaction.
