Deck 15: Principles of Chemical Equilibrium

Question 1

In an equilibrium process,the concentrations of products and of reactants are equal.

Answer 1

False

Question 2

Changes in temperature cause change in the equilibrium position.

Answer 2

True

Question 3

For which of the following reactions does K_p = K_c?

A)3 Fe(s)+ 4 H₂O(g)⇌ Fe₃O₄(s)+ 4 H₂(g)
B)C(s)+ H₂O(g)⇌ CO(g)+ H₂(g)
C)2 SO₂(g)+ O₂(g)⇌ 2 SO₃(g)
D)H₂(g)+ I₂(s)⇌ 2 HI(g)

Answer 3

3 Fe(s)+ 4 H₂O(g)⇌ Fe₃O₄(s)+ 4 H₂(g)

Question 4

What is the value for K_c for the reaction below if the equilibrium concentrations are [N₂] = 0.025 M,[H₂] = 0.0013 M and [NH₃] = 0.028 M for the following reaction?
N₂(g)+ 3 H₂(g)⇌ 2 NH₃(g)

A)8.6 × 10²
B)1.4 × 10⁷
C)1.2 × 10^-3
D)7.1 × 10^-8
E)7.4 × 10⁵

Question 5

The concentration of a pure solid is left out of a equilibrium constant expression but a pure liquid is included.

Question 6

What is the value for K_c if [CO] = 0.025 M,[H₂] = 0.013 M and [CH₃OH] = 0.0028 M for the following reaction?
CH₃OH(g)⇌ CO(g)+ 2 H₂(g)

A)1.5 × 10^-3
B)0.12
C)6.6 × 10²
D)8.6
E)9.1 × 10^-7

Question 7

Both products and reactants will be present in an equilibrium reaction unless K is very small or very large.

Question 8

Which of the following substances present in the chemical reaction would be excluded from the equilibrium constant expression?

A)Na⁺(aq)
B)H₂O(g)
C)Cl^-(aq)
D)H₂O(l)(reactant and solvent)
E)CO(g)

Question 9

The value of the equilibrium constant for a given reaction depends on the initial concentrations of reactants.

Question 10

In a system in equilibrium,two opposing reactions occur at equal rates.

Question 11

Choose the INCORRECT statement.

A)A certain amount of energy,called the activation energy,must be available if a reaction is to take place.
B)A reversible chemical reaction is one in which equilibrium is never established due to the constant decomposition of the products.
C)When the rate of the reverse reaction equals the rate of the forward reaction,equilibrium has been established.
D)Changes in temperature will change the value of an equilibrium constant.
E)Chemical equilibrium is a dynamic equilibrium.

Question 12

Given that the equilibrium concentrations of [N₂] = 0.035 M,[C₂H₂] = 0.057 M,and [HCN] = 6.8 × 10^-4 M,find the value of the equilibrium constant expression for the reaction:
N₂(g)+ C₂H₂(g)⇌ 2 HCN

A)3.4 × 10^-1
B)2.9
C)4300
D)2.3 × 10^-4
E)6.8 × 10^-1

Question 13

For a solute (X)aq,in an ideal aqueous solution,its activity equals its concentration.

Question 14

Given the following:
I.N₂O(g)+ 1/2 O₂(g)⇌ 2 NO(g)K_c = 1.7 × 10^-13
II.N₂(g)+ O₂(g)⇌ 2 NO(g)K_c = 4.1 × 10^-31
Find the value of the equilibrium constant for the following equilibrium reaction:
N₂(g)+ 1/2 O₂(g)⇌ N₂O(g)

A)7.0 × 10^-44
B)4.2 × 10¹⁷
C)2.4 × 10^-18
D)1.6 × 10^-9
E)2.6 × 10^-22

Question 15

Large value for equilibrium constant K means the reaction will be less complete at the equilibrium point.

Question 16

One method to aid in working out equilibrium problems is the ICE table.

Question 17

For the following chemical equilibrium,K_p = 4.6 × 10^-14 at 25 °C,find the value of K_c for this reaction at 25 °C.
2 Cl₂(g)+ 2 H₂O(g)⇌ 4 HCl(g)+ O₂(g)

A)K_c = 1.9 × 10^-15
B)K_c = 2.2 × 10^-14
C)K_c = 1.1 × 10^-12
D)K_c = 9.4 × 10^-14
E)K_c = 4.6 × 10^-14

Question 18

Reaction quotient Q will always be equal to the reaction's equilibrium constant K.

Question 19

Equilibrium reactions are noted by a single straight arrow for a yield sign.

Question 20

For the reaction: H₂(g)+ I₂(g)⇌ 2 HI(g),K_c = 92.0
When equilibrium concentrations of HI and I₂ are [HI] = 0.115 M and [I₂] = 0.250 M,the equilibrium concentration of [H₂] is:

A)5.00 × 10^-3 M
B)5.75 × 10^-4 M
C)1.74 × 10³ M
D)0.135 M
E)9.56 M

Question 21

Choose the correct statement about the equilibrium:
N₂(g)+ 3 H₂(g)⇌ 2 NH₃(g),K_p = 1 × 10^-4

A)The rate constant for the forward reaction is greater than that of the reverse reaction.
B)Since the reaction has a high activation energy,a catalyst is not needed.
C)The equilibrium constant is given by K_p = [N₂][H₂]³/[NH₃]².
D)Conducting the reaction under high pressures will increase the yield of ammonia.
E)The K_p is independent of temperature.

Question 22

For the reaction: CH₄(g)+ 2 H₂O(g)⇌ CO₂(g)+ 4 H₂(g),Δ_rH° = +190 kJ,when catalyst is added:

A)the reaction shifts to the right
B)the reaction shifts to the left
C)the ΔH° increases
D)the temperature increases
E)there is no change,catalyst changes reaction rate only

Question 23

For the reaction: CH₄(g)+ 2 H₂O(g)⇌ CO₂(g)+ 4 H₂(g),ΔH° = +190 kJ,when H₂(g)is added:

A)the reaction shifts to the right
B)the reaction shifts to the left
C)the Δ_rH° increases
D)the temperature increases
E)there is no change in equilibrium position

Question 24

For the reaction: CH₄(g)+ 2 H₂O(g)⇌ CO₂(g)+ 4 H₂(g),Δ_rH° = +190 kJ,when CH₄ is added:

A)the reaction shifts to the right
B)the reaction shifts to the left
C)the Δ_rH° increases
D)the temperature increases
E)there is no change in equilibrium position

Question 25

For the reaction: 3 Fe(s)+ 4 H₂O(g)⇌ Fe₃O₄(s)+ 4 H₂(g)what is the effect on equilibrium of increasing temperature of an exothermic reaction?

A)The reaction shifts to the right.
B)There is no change.
C)The reaction shifts to the left.
D)The K_p is decreased.
E)The K_p is doubled.

Question 26

For the reaction: 3 Fe(s)+ 4 H₂O(g)⇌ Fe₃O₄(s)+ 4 H₂(g)what is the effect of removing H₂?

A)The reaction shifts to the right.
B)There is no change.
C)The reaction shifts to the left.
D)The K_p is decreased.
E)The K_p is doubled.

Question 27

Consider the reaction:
CH₄(g)+ 4 Cl₂(g)⇌ CCl₄(l)+ 4 HCl(g),Δ_rH° = -398 kJ/mol
The equilibrium is displaced to the right if:

A)the temperature is raised
B)the pressure is lowered
C)some carbon tetrachloride is removed
D)some hydrogen chloride is added
E)some chlorine gas is removed

Question 28

In a reaction at equilibrium involving only gases,a change in pressure of the reaction mixture shifts the position of equilibrium only when:

A)heat is absorbed by the reaction proceeding to the right
B)the gases are impure
C)the collision rate increases
D)the reaction is exothermic as written
E)the moles of gas are not equal on the two sides of the equation

Question 29

Choose the correct statement about a container in which the chemical equilibrium is established:
2 SO₂(g)+ O₂(g)⇌ 2 SO₃(g)+ heat

A)A decrease in amount of O₂ will decrease the amount of SO₂ present.
B)A decrease in the volume will decrease the amount of SO₂ present.
C)An increase in temperature will decrease the amount of SO₂ present.
D)A decrease in the amount of SO₃ present will increase the amount of SO₂ present.
E)An increase in amount of O₂ will increase the amount of SO₂ present.

Question 30

For the reaction: CH₄(g)+ 2 H₂O(g)⇌ CO₂(g)+ 4 H₂(g),Δ_rH° = +190 kJ,when the temperature is raised to 1200 K:

A)the reaction shifts to the right
B)the reaction shifts to the left
C)the Δ_rH° increases
D)the temperature increases
E)there is no change in equilibrium position

Question 31

For the reaction 2 SO₂ (g)+ O₂ (g)⇌ 2 SO₃ (g),K_c = 2.8 × 10² at 1000 K.If a vessel is filled with these gases such that the initial concentrations are [SO₂] = 0.025 M,[O₂] = 0.035 M,and [SO₃] = 0.046 M,in which direction will a reaction occur and why?

A)toward products because Q_c = 53
B)toward reactants because Q_c = 0.019
C)toward products because Q_c = 97
D)toward reactants because Q_c = 2.8 × 10³
E)it is at equilibrium because Q_c = 1

Question 32

According to Le Chatelier's Principle:

A)an increase in pressure always causes a change in the position of equilibrium for any reaction
B)the greatest yield of ammonia in the exothermic reaction N₂ + 3 H₂ ⇌ 2 NH₃ is attained at a high temperature
C)the equilibrium constant is increased for the reaction A + B ⇌ C if the concentration of A is increased
D)an increase of temperature causes a decrease in the value of the equilibrium constant for an exothermic reaction
E)when an equilibrium system is stressed,the system reacts to offset the stress

Question 33

For the reaction CO(g)+ 3 H₂(g)⇌ H₂O(g)+ CH₄(g),K_c = 190 at 1000 K.If a vessel is filled with these gases such that the initial concentrations are [CO] = 0.036 M,[H₂] = 0.045 M,[H₂O] = 0.020,M and [CH₄] = 0.031 M,in which direction will a reaction occur and why?

A)toward products because Q_c = 0.38
B)toward reactants because Q_c = 0.24
C)toward products because Q_c = 4.1
D)toward reactants because Q_c = 61
E)it is at equilibrium because Q_c = 190

Question 34

Consider the following reaction.
C(s)+ H₂O(g)⇌ CO(g)+ H₂(g)
At equilibrium at a certain temperature,[H₂O] = 0.12 M,and [CO] = [H₂] = 1.2 M.If suddenly these concentrations are increased by 0.50 M,which of the following is true?

A)more products are formed
B)K_c = 4.66
C)more H₂O(g)will be formed
D)Since K_c does not change,nothing happens.

Question 35

Which factor influences the value of the equilibrium constant for a reversible reaction?

A)addition of a catalyst
B)raising the temperature
C)removing product
D)removing reactant
E)increase in mixing rate

Question 36

Consider the exothermic reaction:
4 HCl(aq)+ MnO₂(s)⇌ Cl₂(g)+ 2 H₂O(l)+ MnCl₂(aq)
The equilibrium is displaced to the left if:

A)catalyst is added
B)pressure is lowered
C)temperature is lowered
D)MnCl₂(aq)is added
E)MnO₂(s)is added

Question 37

Which of the following keep the equilibrium position unchanged?

A)temperature decrease
B)concentration change
C)temperature
D)pressure change
E)homogeneous catalyst

Question 38

Which of the following equilibrium constants-reaction types is INCORRECT?

A)1.4 × 10⁸³ equilibrium reaction-goes to completion.
B)1.6 × 10^-23 equilibrium reaction-does not occur.
C)1.8 × 10^-5 equilibrium reaction-more reactants than products at equilibrium.
D)1.0 equilibrium reaction-equal amounts of products and reactants.
E)3.2 × 10³ equilibrium reaction-more reactants than products at equilibrium.

Question 39

For the reaction PCl₅ (g)⇌ PCl₃ (g)+ Cl₂ (g)K_c = 0.0454 at 261 °C.If a vessel is filled with these gases such that the initial concentrations are [PCl₅] = 0.20 M,[PCl₃] = 0.20 M,and [Cl₂] = 2.5 M,in which direction will a reaction occur and why?

A)toward products because Q_c = 0.56
B)toward reactants because Q_c = 2.5
C)toward products because Q_c = 2.8
D)toward reactants because Q_c = 0.0454
E)it is at equilibrium because Q_c = 1

Question 40

For the reaction CO(g)+ 3 H₂(g)⇌ H₂O(g)+ CH₄(g),K_c = 190 at 1000 K.If a vessel is filled with these gases such that the initial concentrations are [CO] = 0.025 M,[H₂] = 0.045 M,[H₂O] = 0.025,M and [CH₄] = 0.046 M,in which direction will a reaction occur and why?

A)toward products because Q_c = 0.17
B)toward reactants because Q_c = 0.0029
C)toward products because Q_c = 0.35
D)toward reactants because Q_c = 505
E)it is at equilibrium because Q_c = 1

Question 41

What will happen to the equilibrium in the reaction 2 A(g)⇌ B(g)+ C(g),K_c = 1.25 at 300 K,if a catalyst is added?

A)The reaction is forced to the right.
B)The reaction is forced to the left.
C)No change,catalyst only changes the rate.
D)K_c is increased.
E)K_c is decreased.

Question 42

For the decomposition of SO₃(g),K_c = [SO₂]²[O₂]/[SO₃]²,at equilibrium,there are 0.090 mol SO₂,0.110 mol O₂,0.100 mol SO₃ in a 25.0-L container.What is the value of K_c?

A)3.6 × 10^-3
B)0.040
C)2.23
D)0.089
E)7.89

Question 43

Equilibrium constant K is constant except when one varies the:

A)concentrations of the reactants
B)temperature of the reaction
C)concentration of the products
D)partial pressures of the reactants
E)K always remains constant

Question 44

For the production of NO₂,K_c = [NO₂]²/[NO]²[O₂].At equilibrium in a 2.50 L container,there are 3.00 mol NO,4.00 mol O₂ and 22.0 mol NO₂.The value of K_c is ________.

A)13.4
B)33.6
C)5.38
D)0.0116
E)3.75

Question 45

Consider the following reaction at a certain temperature.
2 SO₃(g)⇌ 2 SO₂(g)+ O₂(g)
When the initial concentration of SO₃(g)is 0.128 M,the concentration of oxygen gas at equilibrium is found to be 0.0130 M.Calculate K_c for this reaction.

A)8.45 × 10^-4
B)1.62 × 10^-2
C)7.64 × 10^-5
D)1.47 × 10^-3

Question 46

For the following reaction
O₂(g)⇌ 2 O(g)
What conditions favor production of oxygen atoms?

A)high temperature and low pressure
B)high temperature and high pressure
C)low temperature and low pressure
D)low temperature and high pressure

Question 47

For CO₂(g)+ H₂(g)⇌ CO(g)+ H₂O(g),K_c = [CO][H₂]/[CO₂][H₂],if there are 1.43 mols each of CO and H₂O,0.572 mol H₂ and 4.572 mols CO₂,in a 4.0 L container at equilibrium,what is K_c?

A)0.547
B)0.782
C)1.28
D)0.137
E)2.34

Question 48

Consider the following equilibrium reaction: PCl₃(g)+ Cl₂(g)⇌ PCl₅(g)K_c = 96.2 The equilibrium constant for the decomposition of PCl₅(g)to PCl₃(g)and Cl₂(g)is ________.

A)-K_c
B)
C)
D)
E)

Question 49

0.75 mol of N₂ and 1.20 mol of H₂ are placed in a 3.0 liter container.When the reaction
N₂(g)+ 3 H₂(g)⇌ 2 NH₃(g)reaches equilibrium,[H₂] = 0.100 M.Which of the following is true?

A)[NH₃] = 0.150 M
B)[NH₃] = 0.200 M
C)[N₂] = 0.650 M
D)[N₂] = 0.250 M
E)[NH₃] = [H₂] = 0.05 M

Question 50

For the reaction;N₂(g)+ 3 H₂(g)⇌ 2 NH₃(g),the equilibrium amount of NH₃ will be increased by:
I.increasing the pressure
II.adding H₂
III.removing N₂
IV.decreasing the pressure

A)I,III
B)III only
C)II,III
D)I,II
E)II,IV

Question 51

Consider the reaction:
2 SO₂(g)+ O₂(g)⇌ 2 SO₃(g),Δ_rH° = -196.6 kJ/mol
The equilibrium is displaced to the left if:

A)some sulfur trioxide is removed
B)the temperature is raised
C)some sulfur dioxide is added
D)the pressure is raised
E)the temperature is lowered

Question 52

2.5 moles H₂O and 100 g of C are placed in a 50-L container.At equilibrium for the reaction C(s)+ H₂O(g)⇌ CO(g)+ H₂(g),[H₂] = 0.040 M.Which of the following is true?

A)[CO] = 0.020 M
B)[H₂O] = 0.010 M
C)no carbon is left
D)[H₂O] = 0.020 M
E)[C(s)] = 0.04 M

Question 53

For the reaction: CH₄(g)+ 2 H₂O(g)⇌ CO₂(g)+ 4 H₂(g),Δ_rH° = +190 kJ,add N₂(g)at constant volume and:

A)the reaction reacts to the right
B)the reaction reacts to the left
C)the ΔH° increases
D)the temperature increases
E)there is no change

Question 54

Consider the following gas phase reaction at 25 °C.
N₂(g)+ C₂H₂(g)⇌ 2 HCN(g)
1.600 mol N₂(g)and 1.750 mol C₂H₂(g)are placed in a 1.000 L vessel and the mixture is allowed to react.At equilibrium,there are 1.587 mol N₂(g)in the mixture.What is K_c for this reaction at 25 °C?

A)9.8 × 10^-4
B)9.4 × 10^-3
C)2.5 × 10^-4
D)4.7 × 10^-3
E)6.7 × 10^-5

Question 55

In a reaction at equilibrium involving only gases,a pressure change will shift the reaction only when:

A)heat is absorbed by the reaction proceeding to the right
B)the number of molecules on one side is greater than the number on the other side of the balanced equation
C)the number of molecules increases during the chemical reaction
D)the gases are impure
E)the collision rate increases

Question 56

Consider the following chemical reaction at equilibrium:
2 Cl₂(g)+ 2 H₂O(g)⇌ 4 HCl(g)+ O₂(g)
This equilibrium can be shifted to the right by:

A)removing H₂O(g)from the mixture
B)adding more O₂(g)to the mixture
C)adding Ne(g)to the mixture
D)decreasing the volume of the mixture
E)increasing the volume of the mixture

Question 57

For the reaction below
CO(g)+ 2 H₂(g)⇌ CH₃OH(g)
The equilibrium concentrations at 483 K are [CO] = 0.0753 M,[H₂] = 0.151 M,and [CH₃OH] = 0.0247 M.Calculate the value of K_c.

A)14.4
B)1.09
C)2.17
D)0.0694
E)0.917

Question 58

Consider the following equation:
N₂O₄(g)⇌ 2 NO₂(g),K_c = 5.8 × 10^-3
If the initial concentration of N₂O₄(g)= 0.040 M and the initial concentration of NO₂(g)is 0 M,what is the equilibrium concentration of N₂O₄(g)?

A)1.7 × 10^-2 M
B)1.9 × 10^-2 M
C)3.3 × 10^-2 M
D)2.6 × 10^-2 M
E)2.3 × 10^-6 M

Question 59

What is the equilibrium constant expression for:
4 NH₃(g)+ 5 O₂(g)⇌ 4 NO(g)+ 6 H₂O(g)

A)
B)
C)
D)
E)

Question 60

Write the equilibrium constant expression for the following reaction:
N₂(g)+ 3 H₂(g)⇌ 2 NH₃(g)

A)
B)
C)
D)
E)

Question 61

Write the equilibrium expression K_c for the reaction:
Sodium sulfite(aq)+ chloric acid (aq)⇌ sodium chlorate(aq)+ sulfur dioxide(g)+ water(l).

A)
B)
C)
D)
E)

Question 62

For a reaction,the reaction quotient,Q_c > K_c ,the reaction ________.

A)is at equilibrium
B)is exothermic
C)shifts to the right
D)shifts to the left
E)is endothermic

Question 63

For the reaction:
3 Fe(s)+ 4 H₂O(g)⇌ Fe₃O₄(s)+ 4 H₂(g)
Write the expression for Kp.

A)
B)
C)
D)
E)

Question 64

For the reaction 2 NO₂(g)⇌ N₂O₄(g)K_p equals ________.

A)K_c
B)RT/K_c
C)K_c(RT)
D)K_c/RT
E)K_c(RT)²

Question 65

Two moles of NH₃ are initially present for the reaction:
2 NH₃(g)⇌ N₂(g)+ 3 H₂(g)
At equilibrium there is 1.00 mol NH₃.How many moles of H₂ are present at equilibrium?

A)3.00 moles
B)1.00 moles
C)1.50 moles
D)0.67 moles
E)0.75 moles

Question 66

For the reaction: 3 Fe(s)+ 4 H₂O(g)⇌ Fe₃O₄(s)+ 4 H₂(g)write the expression for K_c in terms of K_p.

A)K_c = K_p
B)K_c =
C)K_c = K_pRT
D)K_c =
E)K_c =

Question 67

What is the relationship between K_p and K_c for the reaction below?
4 NH₃(g)+ 7 O₂(g)⇌ 2 N₂O₄(g)+ 6 H₂O(g)

A)K_p = K_c(RT)^-3
B)K_c = K_p(RT)^-3
C)K_p = K_c(RT)³
D)K_p = K_c(RT)
E)K_p = K_c

Question 68

For the reaction: 3 Fe(s)+ 4 H₂O(g)⇌ Fe₃O₄(s)+ 4 H₂(g)what is the effect of adding Fe(s)?

A)The reaction shifts to the right.
B)There is no change.
C)The reaction shifts to the left.
D)K_p is decreased.
E)K_p is doubled.

Question 69

For the reaction: 2 Cl₂(g)+ 2 H₂O(g)⇌ 4 HCl(g)+ O₂(g),K_p = 6.4 × 10^-6 at 500 K.If a fixed volume is filled with initial concentrations of these gases at 227 °C such that [Cl₂] = 0.5 M,[H₂O] = 0.40 M,[HCl] = 0.5 M,and [O₂] = 0.015 M,in which direction will the reaction proceed?

A)The reaction proceeds to the right.
B)The reaction proceeds to the left.
C)The reaction is already at equilibrium.
D)The reaction volume must be specified to answer this question.
E)The value of K_p at 25 °C must be specified to answer this question.

Question 70

Find K_p for the following reaction at 25.0 °C.
SbCl₅(g)⇌ SbCl₃(g)+ Cl₂(g)K_c = 2.51 × 10^-2

A)0.614
B)1.03 × 10^-3
C)5.15 × 10^-2
D)9.74 × 10²
E)39.8

Question 71

Write the equilibrium constant expression for the following reaction:
2 KI(aq)+ H₂O₂(aq)⇌ 2 KOH(aq)+ I₂(aq)

A)K_c =
B)K_c = [I₂]
C)K_c = [I₂]²
D)K_c =
E)K_c =

Question 72

For the reaction: 2 SO₂(g)+ O₂(g)⇌ 2 SO₃(g),K_c = 6.9 × 10²⁴ at 25 °C.If a reaction vessel is filled with these gases,such that [SO₂] = 6.0 M,[O₂] = 6.0 M and [SO₃] = 6.0 M,in which direction will the reaction proceed?

A)The reaction proceeds to the right.
B)The reaction proceeds to the left.
C)The reaction is already at equilibrium.
D)The reaction volume must be specified to answer this question.
E)The value of K_p must be specified to answer this question.

Question 73

Consider the following hypothetical equilibrium reaction:
A₂(g)+ B₂(g)⇌ 2 AB(g) where K_c =
The equilibrium constant for the reaction: 2 A₂(g)+ 2 B₂(g)⇌ 4 AB(g)is ________.

A)
B)K_c⁴
C)
D)
E)K_c²

Question 74

At a certain temperature,K_c = 0.0500 and △_rH° = +39.6 kJ for the reaction below.
2 MgCl₂(s)+ O₂(g)⇌ 2 MgO(s)+ 2 Cl₂(g)
Calculate K_c for the reaction
MgO(s)+ Cl₂(g)⇌ MgCl₂(s)+ 1/2 O₂(g)
And indicate whether its value will be larger or smaller at a lower temperature.

A)4.47,larger
B)400,smaller
C)0.224,larger
D)0.224,smaller
E)0.0025,smaller

Question 75

Write the equilibrium constant expression for the following reaction:
6 CO₂(g)+ 6 H₂O(l)⇌ C₆H₁₂O₆(s)+ 6 O₂(g)

A)K_c =
B)K_c =
C)K_c =
D)K_c =
E)K_c =

Question 76

Write the equilibrium constant expression for the reaction:
3 Sn(s)+ 4 HNO₃(aq)+ H₂O(l)⇌ 3 H₂SnO₃(s)+ 4 NO(g)

A)K_c =
B)K_c =
C)K_c =
D)K_c =
E)K_c =

Question 77

In the reaction:
2 N₂O(g)+ N₂H₄(g)⇌ 3 N₂(g)+ 2 H₂O(g),
One starts with 0.10 mol N₂O and 0.25 mol N₂H₄ in a 10.0 L container.If there are 0.06 mol N₂O at equilibrium,how many moles of N₂ are present?

A)0.02
B)0.04
C)0.06
D)0.09
E)0.07

Question 78

For 2 NO₂(g)⇌ N₂O₄(g),K_c = [N₂O₄]/[NO₂]².At equilibrium there are 0.0270 mol N₂O₄ and 0.450 mol NO₂ in a 50.0-L container.What is K_c?

A)0.00267
B)6.81
C)6.67
D)0.133
E)2.45

Question 79

Given the following reactions,
2 PCl₃(g)⇌ 2 P(g)+ 3 Cl₂(g)K_c = 0.0667
PCl₃(g)+ Cl₂(g)⇌ PCl₅(g)K_c = 4.0
Calculate K_c for the reaction below.
2 P(g)+ 5 Cl₂(g)⇌ 2 PCl₅(g)

A)240
B)1.1
C)60
D)23
E)0.41

Question 80

For the reaction 2 A(g)⇌ B(g)+ C(g),K_c = 1.25 at 300 K.If a 1.00 L mixture contains 0.619 mol A,0.693 mol B,and 0.689 mol C at 300 K,will the mixture be in equilibrium? If not,in what direction will a net reaction occur?

A)Yes,reaction is at equilibrium.
B)No,net reaction proceeds to the left.
C)No,net reaction proceeds to the right.
D)No,but there is no net reaction.
E)Yes,net reaction proceeds to the right