Textbook Question
If Kc = 7.5×10−9 at 1000 K for the reaction N2(g) + O2(g) → 2 NO(g), give the value of Kc at 1000 K for the reaction
(a) 2 NO(g) → N2(g) + O2(g)
Ch.15 - Chemical Equilibrium
Chapter 15, Problem 15.62b
The reaction 2 AsH31g2 ∆ As21g2 + 3 H21g2 has Kp =
7.2 * 107 at 1073 K. At the same temperature, what is Kp
for each of the following reactions?
(b) 4 AsH31g2 ∆ 2 As21g2 + 6 H21g2
Verified step by step guidance1
Identify the relationship between the given reaction and the new reaction. The new reaction is essentially the given reaction multiplied by 2.
Recall that when a reaction is multiplied by a factor, the equilibrium constant (Kp) for the new reaction is the original Kp raised to the power of that factor.
In this case, the factor by which the original reaction is multiplied is 2.
Calculate the new Kp by raising the original Kp to the power of 2. This means you will calculate (7.2 * 10^7)^2.
The result from the calculation in step 4 will give you the Kp for the new reaction.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Equilibrium Constant (Kp)
The equilibrium constant (Kp) is a numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium for a given reaction, with each concentration raised to the power of its coefficient in the balanced equation. It is specific to a particular temperature and provides insight into the extent of a reaction. A larger Kp indicates a greater concentration of products at equilibrium.
Recommended video:
Guided course
03:20
Equilibrium Constant Expressions
Reaction Stoichiometry
Reaction stoichiometry refers to the quantitative relationship between the reactants and products in a chemical reaction, as represented by the coefficients in a balanced equation. When deriving Kp for a different reaction, it is essential to adjust the coefficients accordingly, as this affects the powers to which the concentrations are raised in the Kp expression. Understanding stoichiometry is crucial for manipulating equilibrium constants.
Recommended video:
Guided course
01:16Stoichiometry Concept
Temperature Dependence of Kp
The value of Kp is temperature-dependent, meaning that changes in temperature can alter the equilibrium position of a reaction. For a given reaction, Kp is only valid at a specific temperature, and any change in temperature will require recalculating Kp. This concept is vital when comparing Kp values for reactions occurring at the same temperature, as in the provided question.
Recommended video:
Guided course
01:24Kw Temperature Dependence
Related Practice
Textbook Question
If Kc = 7.5×10−9 at 1000 K for the reaction N2(g) + O2(g) → 2 NO(g), give the value of Kc at 1000 K for the reaction
(b) NO(g) → 1/2 N2(g) + 1/2 O2(g)
Textbook Question
The reaction 2 AsH31g2 ∆ As21g2 + 3 H21g2 has Kp =
7.2 * 107 at 1073 K. At the same temperature, what is Kp
for each of the following reactions?
(c) 9 H21g2 + 3 As21g2 ∆ 6 AsH31g2
Textbook Question
The reaction
2 PH31g2 + As21g2 ∆ 2 AsH31g2 + P21g2
has Kp = 2.9 * 10-5 at 873 K. At the same temperature,
what is Kp for each of the following reactions?
(a) 2 AsH31g2 + P21g2 ∆ 2 PH31g2 + As21g2
Textbook Question
Calculate the value of the equilibrium constant at 427 °C for the reaction
Na O1s2 + 1>2 O 1g2 ∆ Na O 1s2
given the following equilibrium constants at 427 °C.
Na2O1s2 ∆ 2 Na1l2 + 1>2 O21g2 Kc = 2 * 10-25 Na O 1s2 ∆ 2 Na1l2 + O 1g2 K = 5 * 10-29