Question 1

A mixture of carbon monoxide,hydrogen,and methanol is at equilibrium.The balanced chemical equation is: CO(g)+ 2H₂(g)⇌ CH₃OH(g).At 250°C,the mixture contains 0.0960 M CO,0.191 M H₂,and 0.150 M CH₃OH.What is the value for K_c?

Accepted Answer

D

Question 2

For the reaction: N₂(g)+ 2 O₂(g)⇌ 2 NO₂(g),K_c = 8.3 × 10^-10 at 25°C.What is the concentration of N₂ gas at equilibrium when the concentration of NO₂ is twice the concentration of O₂ gas?

Accepted Answer

Let's assume that the initial concentration of OS1U1B12S1U1B0 is x M. Then, the initial concentration of NOS1U1B12S1U1B0 is 2x M. The initial concentration of NS1U1B12S1U1B0 is 0 M (since it is not given).

At equilibrium, let's assume that the concentration of NS1U1B12S1U1B0 is y M. Then, the concentration of OS1U1B12S1U1B0 becomes (x - 2y) M and the concentration of NOS1U1B12S1U1B0 becomes (2x + y) M.

We can now use the equilibrium constant expression to find the concentration of NS1U1B12S1U1B0:

KS1U1B1cS1U1B0 = [NOS1U1B12S1U1B0]2 / ([NS1U1B12S1U1B0][OS1U1B12S1U1B0]2)
8.3 × 10S1U1P1-10S1S1P0 = (2x + y)2 / (y(x - 2y)2)

Simplifying this expression and rearranging, we get:

y3 - 4xy2 + 4x2y - 8.3 × 10S1U1P1-10S1S1P0yx2 = 0

This is a cubic equation in y, and we can solve it using the cubic formula or numerical methods. However, in this case, the answer choices are all in some multiple of 10S1U1P19S1S1P0 M, which suggests that the problem can be solved using estimates.

Since the equilibrium constant is very small (10S1U1P1-10S1S1P0), we can assume that the concentration of NS1U1B12S1U1B0 is very small compared to the concentrations of OS1U1B12S1U1B0 and NOS1U1B12S1U1B0. This means that we can approximate:

y << x
y << 2x

With these approximations, we can simplify the cubic equation to:

- 8.3 × 10S1U1P1-10S1S1P0x2 ≈ 0

Solving for x, we get:

x ≈ √(8.3 × 10S1U1P1-10S1S1P0) ≈ 9.12 × 10S1U1P-6S1S1P0 M

Using this value of x, we can find y:

KS1U1B1cS1U1B0 = (2x + y)2 / (y(x - 2y)2)
8.3 × 10S1U1P1-10S1S1P0 ≈ (2x)2 / (y(x - 2y)2)
y(x - 2y)2 ≈ (2x)2 / 8.3 × 10S1U1P1-10S1S1P0
y(x2 - 4xy + 4y2) ≈ (2x)2 / 8.3 × 10S1U1P1-10S1S1P0
y(16x2) ≈ (2x)2 / 8.3 × 10S1U1P1-10S1S1P0
y ≈ (2x)2 / (16x2 × 8.3 × 10S1U1P1-10S1S1P0)
y ≈ 4.8 × 10S1U1P19S1S1P0 M

Therefore, the answer is D: 4.8 × 10S1U1P19S1S1P0 M.

Question 3

Given the reaction: 2 HI ⇌ H₂ + I₂.If K_c^' for the reverse reaction is 1.85 × 10^-2 at 425°C,what is K_c for the forward reaction at the same temperature?

Accepted Answer

The equilibrium constant for the forward reaction ($K_c$) is the reciprocal of the equilibrium constant for the reverse reaction. Given $K_c$ for the reverse reaction is $1.85 \times 10^{-2}$, for the forward reaction it is $1 / (1.85 \times 10^{-2}) = 54.1$.

Question 4

Nitric oxide reacts with oxygen to form nitrogen dioxide: 2 NO(g)+ O₂(g)⇌ 2 NO₂(g) What is K_c'for the reverse reaction if the equilibrium concentration of NO is 0.300 M,O₂ is 0.200 M,and NO₂ is 0.530 M at 25°C?

Accepted Answer

The equilibrium constant for the reverse reaction can be found using the expression:

Kc = ( [N2O4] ) / ( [NO]^2 [O2] )

Substituting the given concentrations, we get:

Kc = ( 0.530 ) / ( 0.300^2 * 0.200 )

Kc = 0.0641

Therefore, the answer is B) 0.0641.

Question 5

Which one of the following statements about the equilibrium constant,K_p,is false?

Accepted Answer

The equilibrium constant, K_p, is a ratio of the concentrations of products to reactants at equilibrium, and therefore, molar concentrations should be used in the equilibrium equation, rather than total pressures.

Question 6

If K_c is the equilibrium constant for a forward reaction,2 A⇌ B,what is K_c´ for the reaction 4 A⇌ 2B?

Accepted Answer

The answer of If K_c is the equilibrium constant for...

Question 7

Nitric oxide reacts with oxygen to form nitrogen dioxide: 2 NO(g)+ O₂(g)⇌ 2 NO₂(g) What is K_c for the forward reaction if the equilibrium concentration of NO is 0.200 M,O₂ is 0.100 M,and NO₂ is 0.250 M at 25°C?

Accepted Answer

The answer of Nitric oxide reacts with oxygen to form...

Question 8

If K_c = 7.04 × 10^-2 for the reaction: 2 HBr(g)⇌ H₂(g)+ Br₂(g),what is the value of K_c for the reaction: 1/2 H₂(g)+ 1/2 Br₂(g)== HBr(g)?

Accepted Answer

The answer of If K_c = 7.04 × 10^-2 for...

Question 9

Write the equilibrium equation for the forward reaction: 2 CH₄ (g)+ 3 O₂ (g)⇌ 2 CO (g)+ 4 H₂O (g)

Accepted Answer

The answer of Write the equilibrium equation for the forward...

Question 10

Write the equilibrium equation for the reverse reaction: 2 CH₄ (g)+ 3 O₂ (g)⇌ 2 CO (g)+ 4 H₂O (g)

Accepted Answer

The answer of Write the equilibrium equation for the reverse...

Question 11

If K_c is the equilibrium constant for a forward reaction what is K_c´ for the reverse reaction?

Accepted Answer

The equilibrium constant for the reverse reaction is the reciprocal of the equilibrium constant for the forward reaction, which is mathematically represented as the inverse of the forward reaction's equilibrium constant, hence (K_c)^-1.

Question 12

What is the equilibrium equation for the reaction: NH₄NO₃(s)⇌ N₂O(g)+ 2 H₂O(g)?

Accepted Answer

The answer of What is the equilibrium equation for the...

Question 13

The equilibrium equation is also known as the law of

Accepted Answer

The equilibrium equation is also known as the law of mass action, which states that the rate of a chemical reaction is proportional to the product of the concentrations of the reactants raised to their stoichiometric coefficients.

Question 14

Write the equilibrium equation for the reverse reaction: 2 CH₄(g)+ 3 O₂(g)⇌ 2 CO(g)+ 4 H₂O(g)

Accepted Answer

The answer of Write the equilibrium equation for the reverse...

Question 15

Which of the following statements is false regarding the equilibrium constant,K_c?

Accepted Answer

The equilibrium constant for the reverse reaction is the reciprocal, not the negative, of the equilibrium constant for the forward reaction.

Question 16

If K_c equals 0.11 at 25°C for the reaction: N₂O₄(g)⇌ 2 NO₂(g),what is K_c for the reaction: NO₂(g)⇌ 1/2 N₂O₄(g)?

Accepted Answer

The equilibrium constant for the reverse reaction is the reciprocal of the original reaction's Kc. Additionally, when the stoichiometry is halved, the square root of the reciprocal is taken. Thus, Kc for NO2(g)⇌ 1/2 N2O4(g) is √(1/0.11) ≈ 3.0.

Question 17

Write the equilibrium equation for the forward reaction: 2 CH₄(g)+ 3 O₂(g)⇌ 2 CO(g)+ 4 H₂O(g)

Accepted Answer

The answer of Write the equilibrium equation for the forward...

Question 18

Which statement about the equilibrium constant is true? The value of K_c

Accepted Answer

The equilibrium constant, denoted as K, is dependent on the temperature of the reaction. Changes in temperature can shift the equilibrium position, which would result in a change in the value of K. Therefore, statement C is true. Statements A and B are incorrect because K is a constant value at a specific temperature and does not change with the concentration of products or reactants. Statement D is incorrect because K can change with a change in temperature.

Question 19

K_p is related to K_c by the equation K_p = K_c (RT)ⁿ.What is the value of n for the reaction below? NH₄NO₃(s)⇌ N₂O(g)+ 2 H₂O(g)

Accepted Answer

Since K_p is related to K_c by the equation K_p = K_c (RT)ⁿ, we can compare the coefficients of the species that appear in both compounds. In the given equation, we can see that the coefficient of H₂O(g) changes from 1 to 2, while the coefficients of the other species remain the same. Therefore, n = 2 - 1 = +1. This means that the reaction shifts to the right with an increase in temperature, leading to an increase in the concentration of products (N₂O(g) and H₂O(g)). So, the best choice is option D.

Question 20

Which one of the following statements does not describe the equilibrium state?

Accepted Answer

While the concentrations of the reactants and products may be equal in some cases, this is not a universal feature of equilibrium. For example, in the equilibrium reaction A + 2B ⇌ C + D, it is possible for [A] and [D] to be higher than [B] and [C] at equilibrium, respectively. The key defining feature of equilibrium is that the forward and reverse reactions are occurring at equal rates, leading to a stable concentration of all species involved.

Quiz 13: Chemical Equilibrium

A mixture of carbon monoxide,hydrogen,and methanol is at equilibrium.The balanced chemical equation is: CO(g) + 2H₂(g) ⇌ CH₃OH(g) .At 250°C,the mixture contains 0.0960 M CO,0.191 M H₂,and 0.150 M CH₃OH.What is the value for K_c?

For the reaction: N₂(g) + 2 O₂(g) ⇌ 2 NO₂(g) ,K_c = 8.3 × 10^-10 at 25°C.What is the concentration of N₂ gas at equilibrium when the concentration of NO₂ is twice the concentration of O₂ gas?

Given the reaction: 2 HI ⇌ H₂ + I₂.If K_c^' for the reverse reaction is 1.85 × 10^-2 at 425°C,what is K_c for the forward reaction at the same temperature?

Nitric oxide reacts with oxygen to form nitrogen dioxide: 2 NO(g) + O₂(g) ⇌ 2 NO₂(g) What is K_c'for the reverse reaction if the equilibrium concentration of NO is 0.300 M,O₂ is 0.200 M,and NO₂ is 0.530 M at 25°C?

Which one of the following statements about the equilibrium constant,K_p,is false?

If K_c is the equilibrium constant for a forward reaction,2 A⇌ B,what is K_c´ for the reaction 4 A⇌ 2B?

Nitric oxide reacts with oxygen to form nitrogen dioxide: 2 NO(g) + O₂(g) ⇌ 2 NO₂(g) What is K_c for the forward reaction if the equilibrium concentration of NO is 0.200 M,O₂ is 0.100 M,and NO₂ is 0.250 M at 25°C?

If K_c = 7.04 × 10^-2 for the reaction: 2 HBr(g) ⇌ H₂(g) + Br₂(g) ,what is the value of K_c for the reaction: 1/2 H₂(g) + 1/2 Br₂(g) == HBr(g) ?

Write the equilibrium equation for the forward reaction: 2 CH₄ (g) + 3 O₂ (g) ⇌ 2 CO (g) + 4 H₂O (g)

Write the equilibrium equation for the reverse reaction: 2 CH₄ (g) + 3 O₂ (g) ⇌ 2 CO (g) + 4 H₂O (g)

If K_c is the equilibrium constant for a forward reaction what is K_c´ for the reverse reaction?

What is the equilibrium equation for the reaction: NH₄NO₃(s) ⇌ N₂O(g) + 2 H₂O(g) ?

The equilibrium equation is also known as the law of

Write the equilibrium equation for the reverse reaction: 2 CH₄(g) + 3 O₂(g) ⇌ 2 CO(g) + 4 H₂O(g)

Which of the following statements is false regarding the equilibrium constant,K_c?

If K_c equals 0.11 at 25°C for the reaction: N₂O₄(g) ⇌ 2 NO₂(g) ,what is K_c for the reaction: NO₂(g) ⇌ 1/2 N₂O₄(g) ?

Write the equilibrium equation for the forward reaction: 2 CH₄(g) + 3 O₂(g) ⇌ 2 CO(g) + 4 H₂O(g)

Which statement about the equilibrium constant is true? The value of K_c

K_p is related to K_c by the equation K_p = K_c (RT) ⁿ.What is the value of n for the reaction below? NH₄NO₃(s) ⇌ N₂O(g) + 2 H₂O(g)

Which one of the following statements does not describe the equilibrium state?

Quiz 13: Chemical Equilibrium

A mixture of carbon monoxide,hydrogen,and methanol is at equilibrium.The balanced chemical equation is: CO(g) + 2H2(g) ⇌ CH3OH(g) .At 250°C,the mixture contains 0.0960 M CO,0.191 M H2,and 0.150 M CH3OH.What is the value for Kc?

For the reaction: N2(g) + 2 O2(g) ⇌ 2 NO2(g) ,Kc = 8.3 × 10-10 at 25°C.What is the concentration of N2 gas at equilibrium when the concentration of NO2 is twice the concentration of O2 gas?

Given the reaction: 2 HI ⇌ H2 + I2.If Kc' for the reverse reaction is 1.85 × 10-2 at 425°C,what is Kc for the forward reaction at the same temperature?

Nitric oxide reacts with oxygen to form nitrogen dioxide: 2 NO(g) + O2(g) ⇌ 2 NO2(g) What is Kc' for the reverse reaction if the equilibrium concentration of NO is 0.300 M,O2 is 0.200 M,and NO2 is 0.530 M at 25°C?

Which one of the following statements about the equilibrium constant,Kp,is false?

If Kc is the equilibrium constant for a forward reaction,2 A⇌ B,what is Kc´ for the reaction 4 A⇌ 2B?

Nitric oxide reacts with oxygen to form nitrogen dioxide: 2 NO(g) + O2(g) ⇌ 2 NO2(g) What is Kc for the forward reaction if the equilibrium concentration of NO is 0.200 M,O2 is 0.100 M,and NO2 is 0.250 M at 25°C?

If Kc = 7.04 × 10-2 for the reaction: 2 HBr(g) ⇌ H2(g) + Br2(g) ,what is the value of Kc for the reaction: 1/2 H2(g) + 1/2 Br2(g) == HBr(g) ?

Write the equilibrium equation for the forward reaction: 2 CH4 (g) + 3 O2 (g) ⇌ 2 CO (g) + 4 H2O (g)

Write the equilibrium equation for the reverse reaction: 2 CH4 (g) + 3 O2 (g) ⇌ 2 CO (g) + 4 H2O (g)

If Kc is the equilibrium constant for a forward reaction what is Kc´ for the reverse reaction?

What is the equilibrium equation for the reaction: NH4NO3(s) ⇌ N2O(g) + 2 H2O(g) ?

The equilibrium equation is also known as the law of

Write the equilibrium equation for the reverse reaction: 2 CH4(g) + 3 O2(g) ⇌ 2 CO(g) + 4 H2O(g)

Which of the following statements is false regarding the equilibrium constant,Kc?

If Kc equals 0.11 at 25°C for the reaction: N2O4(g) ⇌ 2 NO2(g) ,what is Kc for the reaction: NO2(g) ⇌ 1/2 N2O4(g) ?

Write the equilibrium equation for the forward reaction: 2 CH4(g) + 3 O2(g) ⇌ 2 CO(g) + 4 H2O(g)

Which statement about the equilibrium constant is true? The value of Kc

Kp is related to Kc by the equation Kp = Kc (RT) n.What is the value of n for the reaction below? NH4NO3(s) ⇌ N2O(g) + 2 H2O(g)

Which one of the following statements does not describe the equilibrium state?

A mixture of carbon monoxide,hydrogen,and methanol is at equilibrium.The balanced chemical equation is: CO(g) + 2H₂(g) ⇌ CH₃OH(g) .At 250°C,the mixture contains 0.0960 M CO,0.191 M H₂,and 0.150 M CH₃OH.What is the value for K_c?

For the reaction: N₂(g) + 2 O₂(g) ⇌ 2 NO₂(g) ,K_c = 8.3 × 10^-10 at 25°C.What is the concentration of N₂ gas at equilibrium when the concentration of NO₂ is twice the concentration of O₂ gas?

Given the reaction: 2 HI ⇌ H₂ + I₂.If K_c^' for the reverse reaction is 1.85 × 10^-2 at 425°C,what is K_c for the forward reaction at the same temperature?

Nitric oxide reacts with oxygen to form nitrogen dioxide: 2 NO(g) + O₂(g) ⇌ 2 NO₂(g) What is K_c'for the reverse reaction if the equilibrium concentration of NO is 0.300 M,O₂ is 0.200 M,and NO₂ is 0.530 M at 25°C?

Which one of the following statements about the equilibrium constant,K_p,is false?

If K_c is the equilibrium constant for a forward reaction,2 A⇌ B,what is K_c´ for the reaction 4 A⇌ 2B?

Nitric oxide reacts with oxygen to form nitrogen dioxide: 2 NO(g) + O₂(g) ⇌ 2 NO₂(g) What is K_c for the forward reaction if the equilibrium concentration of NO is 0.200 M,O₂ is 0.100 M,and NO₂ is 0.250 M at 25°C?

If K_c = 7.04 × 10^-2 for the reaction: 2 HBr(g) ⇌ H₂(g) + Br₂(g) ,what is the value of K_c for the reaction: 1/2 H₂(g) + 1/2 Br₂(g) == HBr(g) ?

Write the equilibrium equation for the forward reaction: 2 CH₄ (g) + 3 O₂ (g) ⇌ 2 CO (g) + 4 H₂O (g)

Write the equilibrium equation for the reverse reaction: 2 CH₄ (g) + 3 O₂ (g) ⇌ 2 CO (g) + 4 H₂O (g)

If K_c is the equilibrium constant for a forward reaction what is K_c´ for the reverse reaction?

What is the equilibrium equation for the reaction: NH₄NO₃(s) ⇌ N₂O(g) + 2 H₂O(g) ?

Write the equilibrium equation for the reverse reaction: 2 CH₄(g) + 3 O₂(g) ⇌ 2 CO(g) + 4 H₂O(g)

Which of the following statements is false regarding the equilibrium constant,K_c?

If K_c equals 0.11 at 25°C for the reaction: N₂O₄(g) ⇌ 2 NO₂(g) ,what is K_c for the reaction: NO₂(g) ⇌ 1/2 N₂O₄(g) ?

Write the equilibrium equation for the forward reaction: 2 CH₄(g) + 3 O₂(g) ⇌ 2 CO(g) + 4 H₂O(g)

Which statement about the equilibrium constant is true? The value of K_c

K_p is related to K_c by the equation K_p = K_c (RT) ⁿ.What is the value of n for the reaction below? NH₄NO₃(s) ⇌ N₂O(g) + 2 H₂O(g)