At $2000^{\circ} \mathrm{C}$ the equilibrium constant for the reaction

$$2 \mathrm{NO}(g) \rightleftharpoons \mathrm{N}_2(g)+\mathrm{O}_2(g)$$

is $K_c=2.4 \times 10^3$. If the initial concentration of $\mathrm{NO}$ is $0.200 \mathrm{M}$, what are the equilibrium concentrations of NO, $\mathrm{N}_2$, and $\mathrm{O}_2$ ?

At

$$1285 ^ { \circ } \mathrm { C }$$

the equilibrium constant for the reaction

$$\mathrm { Br } _ { 2 } ( g ) \rightleftharpoons 2 \mathrm { Br } ( g ) \text { is } K _ { c } = 1.04 \times 10 ^ { - 3 }$$

A 0.200-L vessel containing an equilibrium mixture of the gases has 0.245 g

$$\mathrm { Br } _ { 2 } ( g )$$

in it. What is the mass of Br(g) in the vessel?

At 900 K, the following reaction has

$$K_p = 0.345:$$

$$2 \mathrm { SO } _ { 2 } ( g ) + \mathrm { O } _ { 2 } ( g ) \rightleftharpoons 2 \mathrm { SO } _ { 3 } ( g )$$

In an equilibrium mixture the partial pressures of

$$SO_2$$

and

$$O_2$$

are 0.135 atm and 0.455 atm, respectively. What is the equilibrium partial pressure of

$$SO_3$$

in the mixture?

At

$$100 ^ { \circ } \mathrm { C } , K _ { c } = 0.078$$

for the reaction

$$\mathrm { SO } _ { 2 } \mathrm { Cl } _ { 2 } ( g ) \rightleftharpoons \mathrm { SO } _ { 2 } ( g ) + \mathrm { Cl } _ { 2 } ( g )$$

In an equilibrium mixture of the three gases, the concentration s of

$$\mathrm { SO } _ { 2 } \mathrm { Cl } _ { 2 } \text { and } \mathrm { SO } _ { 2 }$$

are 0.108 Mand 0.052 M, respectively. What is the partial press ure of

$$Cl_2$$

in the equilibrium mixture?

As shown in Table $15.2, K_p$, for the equilibrium

$$\mathrm{N}_2(g)+3 \mathrm{H}_2(g) \rightleftharpoons 2 \mathrm{NH}_3(g)$$

is $4.51 \times 10^{-5}$ at $450^{\circ} \mathrm{C}$. For each of the mixtures listed here, indicate whether the mixture is at equilibrium at $450^{\circ} \mathrm{C}$. If it is not at equilibrium, indicate the direction (toward a product or toward reactants) in which the mixture must shift to achieve equilibrium.

$26 \mathrm{~atm} \mathrm{NH}_3, 42 \mathrm{~atm} \mathrm{H}_2, 202 \mathrm{~atm} \mathrm{~N}_2$.

As shown in Table $15.2, K_p$, for the equilibrium

$$\mathrm{N}_2(g)+3 \mathrm{H}_2(g) \rightleftharpoons 2 \mathrm{NH}_3(g)$$

is $4.51 \times 10^{-5}$ at $450^{\circ} \mathrm{C}$. For each of the mixtures listed here, indicate whether the mixture is at equilibrium at $450^{\circ} \mathrm{C}$. If it is not at equilibrium, indicate the direction (toward a product or toward reactants) in which the mixture must shift to achieve equilibrium.

$35 \mathrm{~atm} \mathrm{NH}_3, 595 \mathrm{~atm} \mathrm{H}_2$, no $\mathrm{N}_2$

As shown in Table $15.2, K_p$, for the equilibrium

$$\mathrm{N}_2(g)+3 \mathrm{H}_2(g) \rightleftharpoons 2 \mathrm{NH}_3(g)$$

is $4.51 \times 10^{-5}$ at $450^{\circ} \mathrm{C}$. For each of the mixtures listed here, indicate whether the mixture is at equilibrium at $450^{\circ} \mathrm{C}$. If it is not at equilibrium, indicate the direction (toward a product or toward reactants) in which the mixture must shift to achieve equilibrium.

$$105 \mathrm{~atm} \mathrm{NH}_3, 35 \mathrm{~atm} \mathrm{~N}_2, 495 \mathrm{~atm} \mathrm{H}_2$$

At

$$100 ^ { \circ } \mathrm { C }$$

the equilibrium constant for the reaction

$$\mathrm { COCl } _ { 2 } ( g ) \rightleftharpoons \mathrm { CO } ( g ) + \mathrm { Cl } _ { 2 } ( g )$$

has the value

$$Kc=2.19 \times 10 ^ { - 10 }$$

Are the following mixtures of

$$\mathrm { COCl } _ { 2 } , \mathrm { CO }$$

and

$$\mathrm { Cl } _ { 2 } \text { at } 100 ^ { \circ } \mathrm { C }$$

at equilibrium? lf not, indicate the direction that the reaction must proceed to achieve equilibrium.

$$\left[ \mathrm { COCl } _ { 2 } \right] = 0.0100 M , [ \mathrm { CO } ] = \left[ \mathrm { Cl } _ { 2 } \right] = 1.48 \times 10 ^ { - 6 } \mathrm { M }$$

At

$$100 ^ { \circ } \mathrm { C }$$

the equilibrium constant for the reaction

$$\operatorname { COCl } _ { 2 } ( g ) \rightleftharpoons \mathrm { CO } ( g ) + \mathrm { Cl } _ { 2 } ( g )$$

has the value

$$K_c= 2.19 \times 10 ^ { - 10 }$$

Are the following mixtures of

$$\mathrm { COCl } _ { 2 } , \mathrm { CO } \ and \ Cl_2 \ at 100 ^ { \circ } \mathrm { C }$$

at equilibrium? lf not, indicate the direction that the reaction must proceed to achieve equilibrium.

$$\begin{array} { l } { \left[ \mathrm { COCl } _ { 2 } \right] = 4.50 \times 10 ^ { - 2 } \mathrm { M } , [ \mathrm { CO } ] = 1.1 \times 10 ^ { - 7 } \mathrm { M } } \\ { \left[ \mathrm { Cl } _ { 2 } \right] = 2.25 \times 10 ^ { - 6 } \mathrm { M } } \end{array}$$

At

$$100 ^ { \circ } C$$

the equilibrium constant for the reaction

$$\mathrm { COCl } _ { 2 } ( g ) \rightleftharpoons \mathrm { CO } ( g ) + \mathrm { Cl } _ { 2 } ( g )$$

has the value

$$Kc = 2.19 \times 10 ^ { - 10 }$$

Are the following mixtures of

$$COCl_2, CO, \ and \ Cl_2$$

at

$$100 ^ { \circ } \mathrm { C }$$

at equilibrium? lf not, indicate the direction that the reaction must proceed to achieve equilibrium.

$$\begin{array} { l } { \left[ \mathrm { COCl } _ { 2 } \right] = 2.00 \times 10 ^ { - 3 } \mathrm { M } , [ \mathrm { CO } ] = 3.3 \times 10 ^ { - 6 } \mathrm { M } } \\ { \left[ \mathrm { Cl } _ { 2 } \right] = 6.62 \times 10 ^ { - 6 } \mathrm { M } } \end{array}$$

At the start of a certain reaction, only reactants are present; no products have been formed. What is the value of

$$Q_c$$

at this point in the reaction?

lf

$$Q _ { c } > K _ { c }$$

how must the reaction proceed to reach equilibrium?

How is a reaction quotient used to determine whether a system is at equilibrium?

What condition must be satisfied so that

$$Q _ { c } = K _ { c } ?$$